Pub Date : 2023-12-15DOI: 10.1177/14680874231214755
Xuelong Miao, Alexander B Chang, Jinbao Zheng, Xu Chen, Lixin Guo, Shaohua Xia, Jian Zhou, Congjin Wang, Zhifeng Zhao, Fudong Xing, Yage Di
The electronic control common rail fuel injection system is one of the key technologies being used in modern diesel engines to improve the engine performance. A numerical simulation was conducted to study the characteristics of the fuel flow around the ball valve in the common rail fuel injector. The lift of the control ball valve and static pressure of the flow field around the control ball valve were measured respectively. The simulation was performed with the measurements as boundary conditions such that the flow characteristics can be correlated with the valve lift and the pressure upstream of the ball valve. Simulation results showed that during the valve opening and closing, a high pressure area appeared below the ball valve, while cavitation appeared in the area around the control ball valve. Specifically, the cavitation mainly appeared around the sealing circle, and its upstream area and the conical surface from the entrance to a certain distance downstream. The flow throttling happened at the outlet orifice under the steady-state condition when the valve was at the maximum opening position. The cavitation around the control ball valve was more serious under higher rail pressure conditions. The formation and development of the cavitation was found to be depending on the lift position of the ball valve and pressure of the flow around the ball valve during the valve opening and valve closing. Higher value of void fraction appeared in the flow when the lift of the ball valve was at a larger opening position. It was found that cavitation around the ball valve will affect the consistency and stability of the fuel flow. And cavitation erosion found at the valve seat from a simplified durability test appeared to be close to the place where cavitation appeared from simulation. Therefore, it is suggested that simulation work can be used to examine if cavitation occurs in the flow path of the control ball valve inside the injector in design phase and make necessary changes on the design to prevent the cavitation and the resulting damages to the control ball valve in the injector.
{"title":"Flow analysis of a control ball valve in a common rail fuel injector","authors":"Xuelong Miao, Alexander B Chang, Jinbao Zheng, Xu Chen, Lixin Guo, Shaohua Xia, Jian Zhou, Congjin Wang, Zhifeng Zhao, Fudong Xing, Yage Di","doi":"10.1177/14680874231214755","DOIUrl":"https://doi.org/10.1177/14680874231214755","url":null,"abstract":"The electronic control common rail fuel injection system is one of the key technologies being used in modern diesel engines to improve the engine performance. A numerical simulation was conducted to study the characteristics of the fuel flow around the ball valve in the common rail fuel injector. The lift of the control ball valve and static pressure of the flow field around the control ball valve were measured respectively. The simulation was performed with the measurements as boundary conditions such that the flow characteristics can be correlated with the valve lift and the pressure upstream of the ball valve. Simulation results showed that during the valve opening and closing, a high pressure area appeared below the ball valve, while cavitation appeared in the area around the control ball valve. Specifically, the cavitation mainly appeared around the sealing circle, and its upstream area and the conical surface from the entrance to a certain distance downstream. The flow throttling happened at the outlet orifice under the steady-state condition when the valve was at the maximum opening position. The cavitation around the control ball valve was more serious under higher rail pressure conditions. The formation and development of the cavitation was found to be depending on the lift position of the ball valve and pressure of the flow around the ball valve during the valve opening and valve closing. Higher value of void fraction appeared in the flow when the lift of the ball valve was at a larger opening position. It was found that cavitation around the ball valve will affect the consistency and stability of the fuel flow. And cavitation erosion found at the valve seat from a simplified durability test appeared to be close to the place where cavitation appeared from simulation. Therefore, it is suggested that simulation work can be used to examine if cavitation occurs in the flow path of the control ball valve inside the injector in design phase and make necessary changes on the design to prevent the cavitation and the resulting damages to the control ball valve in the injector.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"2 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-15DOI: 10.1177/14680874231213142
Marcus Fischer, Jens Achenbach, Stefan Pischinger
Upcoming legislations aim to significantly reduce carbon dioxide and hydrocarbon emissions compared to current regulations. Accordingly, options have to be evaluated to not only convert the raw emissions in a catalytic converter, but also to reduce the raw emissions from the combustion process in the first place. Therefore, thermal piston top land coatings, which lead to an oscillating piston surface temperature were investigated on a single cylinder research engine using a gasoline RON95E10 fuel. Measurements were conducted at a compression ratio of 12.2 and a long Miller intake event. In this manuscript the results achieved with yttria stabilized zirconia in comparison to an uncoated piston are displayed. Significant effects of the coatings on the indicated efficiency could be observed mainly at low engine speeds and loads due to the high share of fuel energy in the wall heat losses and incomplete combustion. At these operating points, the reduction of wall heat losses can almost be fully transferred into indicated efficiency, leading to an increase in indicated efficiency of 6.3% by the yttria stabilized zirconia coating. At higher engine speeds and loads, the advantage in indicated efficiency vanishes and a decrease of 0.5% can be observed. Near full load operation the indicated efficiency slightly lower. However, the effects of a thermal swing coating on combustion efficiency and wall heat losses strongly depend on the operation conditions.
{"title":"Impact of thermal swing piston top land coatings on gasoline engine performance and raw emissions","authors":"Marcus Fischer, Jens Achenbach, Stefan Pischinger","doi":"10.1177/14680874231213142","DOIUrl":"https://doi.org/10.1177/14680874231213142","url":null,"abstract":"Upcoming legislations aim to significantly reduce carbon dioxide and hydrocarbon emissions compared to current regulations. Accordingly, options have to be evaluated to not only convert the raw emissions in a catalytic converter, but also to reduce the raw emissions from the combustion process in the first place. Therefore, thermal piston top land coatings, which lead to an oscillating piston surface temperature were investigated on a single cylinder research engine using a gasoline RON95E10 fuel. Measurements were conducted at a compression ratio of 12.2 and a long Miller intake event. In this manuscript the results achieved with yttria stabilized zirconia in comparison to an uncoated piston are displayed. Significant effects of the coatings on the indicated efficiency could be observed mainly at low engine speeds and loads due to the high share of fuel energy in the wall heat losses and incomplete combustion. At these operating points, the reduction of wall heat losses can almost be fully transferred into indicated efficiency, leading to an increase in indicated efficiency of 6.3% by the yttria stabilized zirconia coating. At higher engine speeds and loads, the advantage in indicated efficiency vanishes and a decrease of 0.5% can be observed. Near full load operation the indicated efficiency slightly lower. However, the effects of a thermal swing coating on combustion efficiency and wall heat losses strongly depend on the operation conditions.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"20 S29","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research, an innovative two-phase fuel transient flow coefficient measurement system is proposed to investigate the flow characteristics and coupling effects of two-phase fuel, and to fill the gap of the two-phase fuel flow characteristics measurement technology of dual fuel injector. For this purpose, microphotography technology is used to obtain the original image of the injector hole, and the accurate area of the injector hole can be obtained by image processing. The two-phase injection momentum and the transient injection pressure are measured by the impact force sensor and the pressure sensor respectively, and the two-phase fuel transient flow coefficient is obtained. Due to the change of the increasing rate of the effective flow area at the nozzle, the gas transient flow coefficient shows two different increasing trends during the upward stage of the gas needle valve. With the background pressure increase, the maximum gas transient flow coefficient decreases and injection duration increases. The influence of pilot diesel injection on subsequent gas injection stages is mainly reflected in that when the gas energizing time is 0.8 ms, the fluctuation range of gas mass flow caused by diesel injection is 52.6%, and the fluctuation range is 14.9% when the gas energizing time is 2 ms, but the influence of diesel injection on the peak value of gas transient flow coefficient can be ignored.
本研究提出了一种创新的两相燃料瞬态流量系数测量系统，用于研究两相燃料的流动特性和耦合效应，填补了双燃料喷射器两相燃料流动特性测量技术的空白。为此，采用显微照相技术获取喷油器孔的原始图像，并通过图像处理获得喷油器孔的精确面积。通过冲击力传感器和压力传感器分别测量两相喷射动量和瞬时喷射压力，得到两相燃料瞬时流量系数。由于喷嘴处有效流通面积增加率的变化，气体瞬态流量系数在气体针阀上升阶段呈现出两种不同的增加趋势。随着背景压力的增加，最大气体瞬态流量系数减小，喷射持续时间增加。先导柴油喷射对后续气体喷射阶段的影响主要体现在，当气体通气时间为 0.8 ms 时，柴油喷射引起的气体质量流量波动范围为 52.6%，当气体通气时间为 2 ms 时，波动范围为 14.9%，但可以忽略柴油喷射对气体瞬态流量系数峰值的影响。
{"title":"Measurements and analyses on the two-phase fuel transient flow characteristics of dual fuel co-direct injector","authors":"Daijun Wei, Canze Ju, Xiyu Yang, Tanqing Zhou, Xiaoyan Wang, Quan Dong","doi":"10.1177/14680874231212691","DOIUrl":"https://doi.org/10.1177/14680874231212691","url":null,"abstract":"In this research, an innovative two-phase fuel transient flow coefficient measurement system is proposed to investigate the flow characteristics and coupling effects of two-phase fuel, and to fill the gap of the two-phase fuel flow characteristics measurement technology of dual fuel injector. For this purpose, microphotography technology is used to obtain the original image of the injector hole, and the accurate area of the injector hole can be obtained by image processing. The two-phase injection momentum and the transient injection pressure are measured by the impact force sensor and the pressure sensor respectively, and the two-phase fuel transient flow coefficient is obtained. Due to the change of the increasing rate of the effective flow area at the nozzle, the gas transient flow coefficient shows two different increasing trends during the upward stage of the gas needle valve. With the background pressure increase, the maximum gas transient flow coefficient decreases and injection duration increases. The influence of pilot diesel injection on subsequent gas injection stages is mainly reflected in that when the gas energizing time is 0.8 ms, the fluctuation range of gas mass flow caused by diesel injection is 52.6%, and the fluctuation range is 14.9% when the gas energizing time is 2 ms, but the influence of diesel injection on the peak value of gas transient flow coefficient can be ignored.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"54 10","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138999203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
How the under-expansion impacts the flash-boiling spray collapse process over wide superheat levels ( Rp, defined as the ratio of saturation pressure to ambient pressure) is not well understood. In the present study, n-hexane flash-boiling sprays issued from a five-hole asymmetrical injector were experimentally and numerically studied to obtain a more general understanding of the spray collapse with wide Rp variation. The experimental results proved that the collapse in the transitional region occurs in the far field, unlike the fully collapse that occurred in the near-nozzle region. The numerical results demonstrated the complexity of individual jet evolutions and their interactions over wide Rp. For individual flash-boiling jets, there were different behaviors in the near-nozzle region. In the case with Rp slightly larger than 1, no shock waves can be observed, but a set of compression-expansion chains. The further increase in Rp caused the generation of shock waves, and resultantly the primary cells were established. For the multi-jet sprays, the further increase in Rp enlarged the primary cells, leading to their interactions and the generation of secondary cells. When Rp was sufficiently higher, the further interactions among primary and secondary cells could cause the generation of tertiary cell. Orderly interactions of shock cells were observed with increasing Rp, that is, the interactions initially occur between the adjacent jets with smaller distances, and then other jets were involved. Based on the results: It was found that the compression-expansion chains caused the low- Rp flash-boiling spray collapse in the far field; With the increase in Rp, the shock waves and shock-to-shock interaction become the main contributor to spray collapse, leading collapse appearing in the near-nozzle region.
人们对膨胀不足如何影响宽过热水平（Rp，定义为饱和压力与环境压力之比）下的闪沸喷雾塌陷过程还不甚了解。在本研究中，对从五孔非对称喷射器喷出的正己烷闪沸喷雾进行了实验和数值研究，以便对 Rp 变化较大时的喷雾塌陷有更全面的了解。实验结果证明，与发生在近喷嘴区域的完全塌陷不同，过渡区域的塌陷发生在远场。数值结果表明了在宽 Rp 条件下单个喷流演变及其相互作用的复杂性。对于单个闪沸射流，在近喷嘴区域有不同的行为。在 Rp 略大于 1 的情况下，没有观察到冲击波，但有一组压缩-膨胀链。Rp 进一步增大会产生冲击波，从而形成原电池。对于多喷嘴喷雾，Rp 的进一步增加扩大了原生细胞，导致它们之间的相互作用，并产生了次生细胞。当 Rp 足够高时，原生细胞和次生细胞之间的进一步相互作用会导致三级细胞的产生。随着 Rp 的增大，冲击细胞的有序相互作用被观察到，即相互作用最初发生在距离较小的相邻射流之间，然后其他射流也参与进来。根据这些结果：研究发现，压缩-膨胀链导致了低 Rp 闪沸喷雾在远场的坍塌；随着 Rp 的增大，冲击波和冲击-冲击相互作用成为喷雾坍塌的主要因素，导致坍塌出现在近喷嘴区域。
{"title":"General understanding on spray collapse process of an asymmetrical multi-hole direct injection gasoline injector under wide flash-boiling conditions","authors":"Jingyu Zhang, Yanfei Li, Hongming Xu, Yang Liu, Xiao Ma, Shijin Shuai","doi":"10.1177/14680874221149244","DOIUrl":"https://doi.org/10.1177/14680874221149244","url":null,"abstract":"How the under-expansion impacts the flash-boiling spray collapse process over wide superheat levels ( Rp, defined as the ratio of saturation pressure to ambient pressure) is not well understood. In the present study, n-hexane flash-boiling sprays issued from a five-hole asymmetrical injector were experimentally and numerically studied to obtain a more general understanding of the spray collapse with wide Rp variation. The experimental results proved that the collapse in the transitional region occurs in the far field, unlike the fully collapse that occurred in the near-nozzle region. The numerical results demonstrated the complexity of individual jet evolutions and their interactions over wide Rp. For individual flash-boiling jets, there were different behaviors in the near-nozzle region. In the case with Rp slightly larger than 1, no shock waves can be observed, but a set of compression-expansion chains. The further increase in Rp caused the generation of shock waves, and resultantly the primary cells were established. For the multi-jet sprays, the further increase in Rp enlarged the primary cells, leading to their interactions and the generation of secondary cells. When Rp was sufficiently higher, the further interactions among primary and secondary cells could cause the generation of tertiary cell. Orderly interactions of shock cells were observed with increasing Rp, that is, the interactions initially occur between the adjacent jets with smaller distances, and then other jets were involved. Based on the results: It was found that the compression-expansion chains caused the low- Rp flash-boiling spray collapse in the far field; With the increase in Rp, the shock waves and shock-to-shock interaction become the main contributor to spray collapse, leading collapse appearing in the near-nozzle region.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"15 3","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138972127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.1177/14680874231213134
Yipeng Yao, Zhiqiang Han, Wei Tian, Geng-Yi He, Yi Wu, Yan Yan, Qi Xia, Jia Fang, Marie-Eve Duprez, Guy De Weireld
Fouling is one of the barriers to developing more efficient and near-zero emission internal combustion engines. The micron-sized particulate matter is one of the roots of this fouling phenomenon in exhaust gas recirculation (EGR) coolers. This fouling is inadequately evaluated quantitatively, and its deposition mechanism is unknown. To investigate the effect of gravity on the deposition of micron-sized particles, an original nondestructive sampling fouling method and experiment apparatus have been developed to effectively obtain the upper and lower bottom fouling in the cooler in the direction of airflow, and the area proportion, count, and diameter of large particles in the fouling using image processing software. It was found that (i) the area proportion of large particles in the lower bottom fouling was almost 2.5 times higher than the upper bottom fouling; (ii) the count of large particles in the lower bottom fouling was higher, and the maximum diameter was larger, up to 639 μm; (iii) the mass of the lower bottom fouling was 1.5 times higher than the upper bottom fouling; (iv) gravity can significantly promote the deposition of micron-sized particles and should be considered in the design and arrangement of the EGR cooler to prevent fouling.
{"title":"An original nondestructive sampling method to study the effect of gravity on the deposition of micron-sized large particles in exhaust gas recirculation (EGR) cooler fouling","authors":"Yipeng Yao, Zhiqiang Han, Wei Tian, Geng-Yi He, Yi Wu, Yan Yan, Qi Xia, Jia Fang, Marie-Eve Duprez, Guy De Weireld","doi":"10.1177/14680874231213134","DOIUrl":"https://doi.org/10.1177/14680874231213134","url":null,"abstract":"Fouling is one of the barriers to developing more efficient and near-zero emission internal combustion engines. The micron-sized particulate matter is one of the roots of this fouling phenomenon in exhaust gas recirculation (EGR) coolers. This fouling is inadequately evaluated quantitatively, and its deposition mechanism is unknown. To investigate the effect of gravity on the deposition of micron-sized particles, an original nondestructive sampling fouling method and experiment apparatus have been developed to effectively obtain the upper and lower bottom fouling in the cooler in the direction of airflow, and the area proportion, count, and diameter of large particles in the fouling using image processing software. It was found that (i) the area proportion of large particles in the lower bottom fouling was almost 2.5 times higher than the upper bottom fouling; (ii) the count of large particles in the lower bottom fouling was higher, and the maximum diameter was larger, up to 639 μm; (iii) the mass of the lower bottom fouling was 1.5 times higher than the upper bottom fouling; (iv) gravity can significantly promote the deposition of micron-sized particles and should be considered in the design and arrangement of the EGR cooler to prevent fouling.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"21 4","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138971962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.1177/14680874231214010
Frederico Falcão Weissinger, Caio Henrique Rufino, Alexander Peñaranda Mendoza, André Luiz Martelli, Eugênio Coelho, Vincent Bigliardi, P. Teixeira Lacava
Plug-in hybrid electric vehicles (PHEV) have the potential of combining the benefits of a renewable electric mix with biofuels. More recently, PHEV have been designed to be equipped with a small combustion engine known as range extender (RE), thus allowing an improvement in vehicle’s range while converting fuel energy through a highly efficient path. Despite being a convenient strategy for decarbonizing light vehicles, the intermittent operation of the engine may create issues regarding the catalytic conversion of pollutants, yielding an increase in local harmful emissions. This drawback may be intensified depending on the used fuel. Hydrous ethanol is a promising alternative for gasoline and is already available in some countries, such as Brazil. However, ethanol has a great enthalpy of vaporization and it results in a charge cooling, affecting the catalyst warm-up and making the intermittent operation with ethanol more challenging. Hence, this study was motivated by the need of improving the catalytic efficiency of flexfuel RE operating with both gasoline and hydrous ethanol. Thus, a calibration was firstly performed to shorten the warm-up phase with ethanol. Then, an electrical heater was employed for accelerated catalyst heating, further improving emissions from ethanol operation, aiming at attaining future emissions regulations. Experimental tests were conducted in a vehicle under FTP72 cycle using a chassis dynamometer. The calibration adjustments resulted in a warm-up phase for ethanol <10 s longer than that for gasoline. The stable operation phase resulted in similar emissions for both fuels. On the cycle average, a reduction in CO for ethanol was observed, and although the methane and NOx emissions were slightly increased due to colder catalyst operation, significant improvements were obtained on a well-to-wheel (WTW) analysis. The use of an electrically heated catalyst (EHC) improved the emissions during the warm-up phase, significantly reducing the emission of NOx and non-methane organic compounds.
插电式混合动力电动汽车（PHEV）具有将可再生电力组合与生物燃料相结合的潜力。最近，PHEV 在设计上配备了被称为增程器（RE）的小型内燃机，从而在通过高效路径转换燃料能量的同时，提高了车辆的续航里程。尽管这是实现轻型车辆脱碳的一种便捷策略，但发动机的间歇性运行可能会造成污染物催化转化方面的问题，从而增加当地的有害气体排放。使用的燃料不同，这一缺点也会加剧。含水乙醇是一种很有前途的汽油替代品，在巴西等一些国家已经可以使用。然而，乙醇的汽化焓很高，会导致装料冷却，影响催化剂预热，使乙醇的间歇运行更具挑战性。因此，本研究的动机是提高使用汽油和含水乙醇的柔性燃料 RE 的催化效率。因此，首先进行了校准，以缩短乙醇的预热阶段。然后，采用电加热器加速催化剂加热，进一步改善乙醇运行时的排放，以达到未来排放法规的要求。使用底盘测功机对 FTP72 循环下的车辆进行了实验测试。通过校准调整，乙醇的预热阶段比汽油长 10 秒。在稳定运行阶段，两种燃料的排放量相似。从循环平均值来看，乙醇的一氧化碳排放量有所减少，虽然甲烷和氮氧化物排放量因催化剂低温运行而略有增加，但在从井到车轮（WTW）的分析中却得到了显著改善。电加热催化剂（EHC）的使用改善了预热阶段的排放，显著减少了氮氧化物和非甲烷有机化合物的排放。
{"title":"Electrically heated catalyst enabling pollutants reduction in hybrid vehicles fueled with ethanol","authors":"Frederico Falcão Weissinger, Caio Henrique Rufino, Alexander Peñaranda Mendoza, André Luiz Martelli, Eugênio Coelho, Vincent Bigliardi, P. Teixeira Lacava","doi":"10.1177/14680874231214010","DOIUrl":"https://doi.org/10.1177/14680874231214010","url":null,"abstract":"Plug-in hybrid electric vehicles (PHEV) have the potential of combining the benefits of a renewable electric mix with biofuels. More recently, PHEV have been designed to be equipped with a small combustion engine known as range extender (RE), thus allowing an improvement in vehicle’s range while converting fuel energy through a highly efficient path. Despite being a convenient strategy for decarbonizing light vehicles, the intermittent operation of the engine may create issues regarding the catalytic conversion of pollutants, yielding an increase in local harmful emissions. This drawback may be intensified depending on the used fuel. Hydrous ethanol is a promising alternative for gasoline and is already available in some countries, such as Brazil. However, ethanol has a great enthalpy of vaporization and it results in a charge cooling, affecting the catalyst warm-up and making the intermittent operation with ethanol more challenging. Hence, this study was motivated by the need of improving the catalytic efficiency of flexfuel RE operating with both gasoline and hydrous ethanol. Thus, a calibration was firstly performed to shorten the warm-up phase with ethanol. Then, an electrical heater was employed for accelerated catalyst heating, further improving emissions from ethanol operation, aiming at attaining future emissions regulations. Experimental tests were conducted in a vehicle under FTP72 cycle using a chassis dynamometer. The calibration adjustments resulted in a warm-up phase for ethanol <10 s longer than that for gasoline. The stable operation phase resulted in similar emissions for both fuels. On the cycle average, a reduction in CO for ethanol was observed, and although the methane and NOx emissions were slightly increased due to colder catalyst operation, significant improvements were obtained on a well-to-wheel (WTW) analysis. The use of an electrically heated catalyst (EHC) improved the emissions during the warm-up phase, significantly reducing the emission of NOx and non-methane organic compounds.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"22 3","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139002419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-14DOI: 10.1177/14680874231214575
Federico Ramognino, L. Sforza, T. Lucchini, C. Welch, Benjamin Böhm, A. Onorati
Control of the combustion process in Spark-Ignition (SI) engines operated with extreme dilution from exhaust gas re-circulation (EGR) represents one of the major limitations in the industrial design of such technology. Numerical approaches able to describe in detail the formation of the early flame kernel become essential to face such an ambitious task. This work presents a RANS-based multi-dimensional model of the combustion process, including an advanced description of the ignition stage to consider its stochastic re-ignitions within the average cycle prediction. The spark-channel is described as a column of Lagrangian parcels that represent early flame kernels, whose growth is controlled by the laminar flame speed and energy input from the electrical circuit. The spatial evolution of each parcel is computed according to a scaled value of the average-flow speed, to mimic the smooth but short elongation of the mean-cycle channel produced by stochastic restrikes affecting the single-cycle arcs. To clarify this phenomenon and assess the proposed CFD method, a series of experiments are performed in a single cylinder SI engine with optical access, running at a low-load cruise-speed operating condition. Increasing EGR levels are tested up to the onset of misfire, with measurements of the secondary-circuit features and of the flame evolution through high-speed imaging. Satisfactory results are achieved in terms of numerical-experimental comparison of the cycle-averaged in-cylinder pressure, discharge parameters, and spatial flame distribution, demonstrating the reliability of the proposed numerical approach.
控制火花点火（SI）发动机在废气再循环（EGR）极度稀释的情况下的燃烧过程是此类技术工业设计的主要限制之一。能够详细描述早期火焰内核形成的数值方法对于完成这样一项艰巨的任务至关重要。本研究提出了一种基于 RANS 的燃烧过程多维模型，包括对点火阶段的高级描述，以考虑平均循环预测中的随机再点火。火花通道被描述为一列拉格朗日包裹，代表早期火焰核，其增长受层流火焰速度和电路能量输入的控制。每个包裹的空间演化都是根据平均流速的比例值计算的，以模拟平均循环通道因随机重击影响单循环弧线而产生的平滑但短暂的伸长。为了澄清这一现象并评估所提出的 CFD 方法，我们在一台带有光学通道的单缸 SI 发动机上进行了一系列实验，该发动机在低负荷巡航速度工作条件下运行。通过高速成像对二次回路特征和火焰演变进行测量，测试了 EGR 水平的增加直至失火的发生。在循环平均缸内压力、排放参数和空间火焰分布的数值-实验比较方面取得了令人满意的结果，证明了所提出的数值方法的可靠性。
{"title":"A CFD ignition model to predict average-cycle combustion in SI engines with extreme EGR levels","authors":"Federico Ramognino, L. Sforza, T. Lucchini, C. Welch, Benjamin Böhm, A. Onorati","doi":"10.1177/14680874231214575","DOIUrl":"https://doi.org/10.1177/14680874231214575","url":null,"abstract":"Control of the combustion process in Spark-Ignition (SI) engines operated with extreme dilution from exhaust gas re-circulation (EGR) represents one of the major limitations in the industrial design of such technology. Numerical approaches able to describe in detail the formation of the early flame kernel become essential to face such an ambitious task. This work presents a RANS-based multi-dimensional model of the combustion process, including an advanced description of the ignition stage to consider its stochastic re-ignitions within the average cycle prediction. The spark-channel is described as a column of Lagrangian parcels that represent early flame kernels, whose growth is controlled by the laminar flame speed and energy input from the electrical circuit. The spatial evolution of each parcel is computed according to a scaled value of the average-flow speed, to mimic the smooth but short elongation of the mean-cycle channel produced by stochastic restrikes affecting the single-cycle arcs. To clarify this phenomenon and assess the proposed CFD method, a series of experiments are performed in a single cylinder SI engine with optical access, running at a low-load cruise-speed operating condition. Increasing EGR levels are tested up to the onset of misfire, with measurements of the secondary-circuit features and of the flame evolution through high-speed imaging. Satisfactory results are achieved in terms of numerical-experimental comparison of the cycle-averaged in-cylinder pressure, discharge parameters, and spatial flame distribution, demonstrating the reliability of the proposed numerical approach.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"2015 28","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139001754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-09DOI: 10.1177/14680874231212250
Binyang Wu, Minshuo Shi, Zhenyuan Zi, Shouying Jin
The application of mechanisms such as exhaust gas recirculation (EGR) coupled with variable valve timing (VVT) and a variable geometry turbocharger (VGT) can improve engine efficiency; however, the energy laws and loss distribution after EGR, VVT, and VGT changes are unclear, restricting the optimization of engine structures and corresponding strategies. Herein, a six-cylinder engine is studied, revealing that the cooling loss of the high-pressure (HP) EGR loop is an important factor affecting the engine energy distribution. The cooling loss accounts for 10.00%–20.00% of the total energy, with an average increase of 1.73%, surpassing other energy losses growth rates. The low-pressure (LP) EGR loop considerably reduces cooling losses. The cooling loss of the LP EGR loop is only 64.05% of the HP EGR loop at a 20% EGR rate. When the EGR rate is >10%, the resulting lower cooling losses effectively improve the engine efficiency and the indicated thermal efficiency (ITE) of the LP EGR loop is 0.20%–0.33% higher than that of the HP EGR loop; when the EGR rate is 21%, the ITE of the LP EGR loop reaches 49.52%. By studying the variation in exergy with operating parameters, it is found that while increasing the EGR rate from 15% to 20%, the proportion of available exergy increases by adjusting the VVT to −85° crank angle after top dead center (CA ATDC) or adjusting the VGT to 47.5% under the original operating scheme of the LP EGR loop (−146° CA ATDC; VGT = 42.5%). The available exergy increases from 71.22%–71.42% (−146° CA ATDC; VGT = 42.5%; original device) to 71.88%–71.58% (−146° CA ATDC; VGT = 47.5%) and 72.02%–72.21% (−85° CA ATDC; VGT = 42.5%). This study explores the energy distribution under different operating schemes, providing theoretical guidance for further improving the thermal efficiency of the entire device.
{"title":"Influence of cooling loss on the energy and exergy distribution of heavy-duty diesel engines based on two-stage variable supercharging, VVT, and EGR","authors":"Binyang Wu, Minshuo Shi, Zhenyuan Zi, Shouying Jin","doi":"10.1177/14680874231212250","DOIUrl":"https://doi.org/10.1177/14680874231212250","url":null,"abstract":"The application of mechanisms such as exhaust gas recirculation (EGR) coupled with variable valve timing (VVT) and a variable geometry turbocharger (VGT) can improve engine efficiency; however, the energy laws and loss distribution after EGR, VVT, and VGT changes are unclear, restricting the optimization of engine structures and corresponding strategies. Herein, a six-cylinder engine is studied, revealing that the cooling loss of the high-pressure (HP) EGR loop is an important factor affecting the engine energy distribution. The cooling loss accounts for 10.00%–20.00% of the total energy, with an average increase of 1.73%, surpassing other energy losses growth rates. The low-pressure (LP) EGR loop considerably reduces cooling losses. The cooling loss of the LP EGR loop is only 64.05% of the HP EGR loop at a 20% EGR rate. When the EGR rate is >10%, the resulting lower cooling losses effectively improve the engine efficiency and the indicated thermal efficiency (ITE) of the LP EGR loop is 0.20%–0.33% higher than that of the HP EGR loop; when the EGR rate is 21%, the ITE of the LP EGR loop reaches 49.52%. By studying the variation in exergy with operating parameters, it is found that while increasing the EGR rate from 15% to 20%, the proportion of available exergy increases by adjusting the VVT to −85° crank angle after top dead center (CA ATDC) or adjusting the VGT to 47.5% under the original operating scheme of the LP EGR loop (−146° CA ATDC; VGT = 42.5%). The available exergy increases from 71.22%–71.42% (−146° CA ATDC; VGT = 42.5%; original device) to 71.88%–71.58% (−146° CA ATDC; VGT = 47.5%) and 72.02%–72.21% (−85° CA ATDC; VGT = 42.5%). This study explores the energy distribution under different operating schemes, providing theoretical guidance for further improving the thermal efficiency of the entire device.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"7 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138585935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-09DOI: 10.1177/14680874231210611
Xu Zhang, G. Shaver, Dheeraj B. Gosala, Carlos A Lana, Dat D. Le, David Langenderfer
Accurate estimation and prediction of engine gas exchange system and in-cylinder conditions are critical for spark-ignited engine control and diagnostic algorithm development. In this paper, a physically-based, control-oriented model for a 2.8 l turbocharged, variable valve timing (VVT) and low pressure (LP) exhaust gas recirculation (EGR)-utilizing SI engine was developed. The model includes the impact of modulation to any combination of 10 actuators, including the throttle valve, compressor bypass valve, fueling rate, waste-gate, LP EGR valve, number of deactivated cylinders, intake valve open (IVO) timing, intake valve close (IVC) timing, exhaust valve open (EVO) timing and exhaust valve close (EVC) timing. The accuracy of the model in capturing engine dynamics was demonstrated by validating it against high-fidelity engine GT-Power simulation results for various drive cycles, particularly emphasizing elevated loads. In comparison to the open literature, novel contributions of the effort described in this paper includes in-cylinder gas composition modeling and turbine-out pressure estimation.
{"title":"Physically-based control-oriented modeling for turbocharged stoichiometric spark-ignited engine with cooled EGR and flexible VVT systems","authors":"Xu Zhang, G. Shaver, Dheeraj B. Gosala, Carlos A Lana, Dat D. Le, David Langenderfer","doi":"10.1177/14680874231210611","DOIUrl":"https://doi.org/10.1177/14680874231210611","url":null,"abstract":"Accurate estimation and prediction of engine gas exchange system and in-cylinder conditions are critical for spark-ignited engine control and diagnostic algorithm development. In this paper, a physically-based, control-oriented model for a 2.8 l turbocharged, variable valve timing (VVT) and low pressure (LP) exhaust gas recirculation (EGR)-utilizing SI engine was developed. The model includes the impact of modulation to any combination of 10 actuators, including the throttle valve, compressor bypass valve, fueling rate, waste-gate, LP EGR valve, number of deactivated cylinders, intake valve open (IVO) timing, intake valve close (IVC) timing, exhaust valve open (EVO) timing and exhaust valve close (EVC) timing. The accuracy of the model in capturing engine dynamics was demonstrated by validating it against high-fidelity engine GT-Power simulation results for various drive cycles, particularly emphasizing elevated loads. In comparison to the open literature, novel contributions of the effort described in this paper includes in-cylinder gas composition modeling and turbine-out pressure estimation.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"2 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138585753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1177/14680874221106168
Saana Hautala, Maciej Mikulski, Emma Söderäng, Xiaoguo Storm, Seppo Niemi
System complexity is challenging for development of marine mid-speed engines when striving to meet increasingly stringent emission targets. Control-oriented modeling offers a solution, cutting calibration time and enabling robust control strategies. Simultaneously, real-time, physics-based engine models (digital twins) are emerging as they offer better predictive capability and scalability than typical mean-value, data-driven approaches. This study explored development of a control-oriented digital twin of a Wärtsilä 4L20 marine engine. Starting from a detailed one-dimensional model (GT-Suite), it explored reduction strategies toward a fast-running engine model (FRM), balancing the calculation speed and accuracy trade-off. Finally, the FRM was tested for real-time implementation on a target machine. Comprehensive experimental data from the 4L20 platform in the VEBIC Engine Laboratory provided the baseline for model calibration. Model calibration and validation covered four representative operating points and involved correlation of crank-angle, resolved in-cylinder pressures, thermal state at several locations of the engine air-path and relevant performance indicators. The results shed new light on the feasibility of digital twins in the marine engine domain. The obtained FRM was three times faster than real-time, while the accuracy loss was comfortably within the 5% tolerance levels for the governing outputs, including crank angle resolved in-cylinder pressure. The grid-resolved simulation was obtained with four times fewer flow components and internal discretization length of 100% and 150% of the cylinder bore for intake and exhaust components respectively. The balance between predictivity, accuracy and real-time surplus, was ultimately more favorable than in state of the art automotive applications and enables exploring further coupling with semi-predictive emission sub-models. The real-time capable FRM is considered applicable in hardware-in-the-loop simulation, and this application is scheduled in a follow-up project.
{"title":"Toward a digital twin of a mid-speed marine engine: From detailed 1D engine model to real-time implementation on a target platform","authors":"Saana Hautala, Maciej Mikulski, Emma Söderäng, Xiaoguo Storm, Seppo Niemi","doi":"10.1177/14680874221106168","DOIUrl":"https://doi.org/10.1177/14680874221106168","url":null,"abstract":"System complexity is challenging for development of marine mid-speed engines when striving to meet increasingly stringent emission targets. Control-oriented modeling offers a solution, cutting calibration time and enabling robust control strategies. Simultaneously, real-time, physics-based engine models (digital twins) are emerging as they offer better predictive capability and scalability than typical mean-value, data-driven approaches. This study explored development of a control-oriented digital twin of a Wärtsilä 4L20 marine engine. Starting from a detailed one-dimensional model (GT-Suite), it explored reduction strategies toward a fast-running engine model (FRM), balancing the calculation speed and accuracy trade-off. Finally, the FRM was tested for real-time implementation on a target machine. Comprehensive experimental data from the 4L20 platform in the VEBIC Engine Laboratory provided the baseline for model calibration. Model calibration and validation covered four representative operating points and involved correlation of crank-angle, resolved in-cylinder pressures, thermal state at several locations of the engine air-path and relevant performance indicators. The results shed new light on the feasibility of digital twins in the marine engine domain. The obtained FRM was three times faster than real-time, while the accuracy loss was comfortably within the 5% tolerance levels for the governing outputs, including crank angle resolved in-cylinder pressure. The grid-resolved simulation was obtained with four times fewer flow components and internal discretization length of 100% and 150% of the cylinder bore for intake and exhaust components respectively. The balance between predictivity, accuracy and real-time surplus, was ultimately more favorable than in state of the art automotive applications and enables exploring further coupling with semi-predictive emission sub-models. The real-time capable FRM is considered applicable in hardware-in-the-loop simulation, and this application is scheduled in a follow-up project.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":" 7","pages":"4553 - 4571"},"PeriodicalIF":2.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138620147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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