A prompt gamma neutron activation analysis (PGNAA) system based on a deuterium-deuterium (D-D) sealed neutron generator was designed using the MOCA code for explosive detection. The system is mainly composed of four parts: D-D sealed neutron generator, moderator, shielding, and Lutetium Yttrium OxyorthoSilicate (LYSO) scintillation detectors. Polyethylene (PE) was selected as the moderator and the optimal thickness was 7cm. Lead, PE, and boron-containing polyethylene were used as shielding materials. In the optimized model, the LYSO detector is used to measure eighteen materials, such as wood, melamine, glucose, and nylon, and so on. Firstly, the nitrogen characteristic peak of 10.8 MeV was analyzed to determine whether the material contained nitrogen. Then, the ratio of characteristic peak counts of C/O and O/N were calculated to distinguish explosives from nitrogen containing materials. Finally, dinitrobenzene, nitroglycerin, TNT, and ammonium nitrate can be separated from nitrogenous substances by a discriminant algorithm. The final device can be used to detect the chemical composition of the threat substances, and the maximum dose rate of the system meets the limits of international protection standards.
{"title":"Simulation Research on Explosives Detection System Based on D-D Sealed Neutron Generator","authors":"Yadong Gao, De-Dong He, Ke Gong, Guang Shi, Si-Yuan Chen, Chen Zhu, Shiwei Jing","doi":"10.1115/power2021-65387","DOIUrl":"https://doi.org/10.1115/power2021-65387","url":null,"abstract":"\u0000 A prompt gamma neutron activation analysis (PGNAA) system based on a deuterium-deuterium (D-D) sealed neutron generator was designed using the MOCA code for explosive detection. The system is mainly composed of four parts: D-D sealed neutron generator, moderator, shielding, and Lutetium Yttrium OxyorthoSilicate (LYSO) scintillation detectors. Polyethylene (PE) was selected as the moderator and the optimal thickness was 7cm. Lead, PE, and boron-containing polyethylene were used as shielding materials. In the optimized model, the LYSO detector is used to measure eighteen materials, such as wood, melamine, glucose, and nylon, and so on. Firstly, the nitrogen characteristic peak of 10.8 MeV was analyzed to determine whether the material contained nitrogen. Then, the ratio of characteristic peak counts of C/O and O/N were calculated to distinguish explosives from nitrogen containing materials. Finally, dinitrobenzene, nitroglycerin, TNT, and ammonium nitrate can be separated from nitrogenous substances by a discriminant algorithm. The final device can be used to detect the chemical composition of the threat substances, and the maximum dose rate of the system meets the limits of international protection standards.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85713715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A numerical study is carried out to investigate the effect of porous fins in counter-flow Double Pipe Heat Exchanger (DPHE). Four DPHE with different porous fin arrangements is simulated for varying Darcy number, fin height, and the number of fins and compared with the conventional DPHE with no porous fins. The Darcy-Brinkman-Forchheimer equation is employed to model the flow in the porous fins considering fixed Re = 100. Al2O3-H2O nanofluid and water are used as hot and cold fluids respectively. Stainless steel is used as porous material with a porosity of 0.65. Results are evaluated in terms of effectiveness and Performance Evaluation Criterion (PEC). The effectiveness of the heat exchanger is used to analyze the heat transfer characteristics whereas the PEC is used to analyze the heat transfer characteristics considering pressure losses also. We evaluated maximum enhancement in thermal performance using effectiveness analysis and through PEC study we evaluated optimal effectiveness and corresponding design parameters. It is shown that utilizing porous fins in DPHE enhances the heat transfer by 134.3%. However, along with enhancement in heat transfer, the pressure losses also enhance which makes the application of porous fin non-viable. Therefore, using the PEC study we obtained optimal design parameters (Da = 10−3, hf = 4 cm, and n = 30) which adapts porous fin viable with enhancement in heat transfer by 66.38%.
对多孔翅片在逆流式双管换热器中的作用进行了数值研究。模拟了4种不同多孔翅片布置方式的DPHE，计算了不同的达西数、翅片高度和翅片数量，并与常规无多孔翅片布置的DPHE进行了比较。考虑固定Re = 100时，采用Darcy-Brinkman-Forchheimer方程模拟多孔翅片内的流动。Al2O3-H2O纳米流体和水分别作为热流体和冷流体。不锈钢作为多孔材料，其孔隙率为0.65。根据有效性和绩效评价标准(PEC)对结果进行评价。利用换热器的效率分析换热特性，同时利用PEC分析考虑压力损失的换热特性。我们通过有效性分析评估了热性能的最大增强，并通过PEC研究评估了最佳有效性和相应的设计参数。结果表明，采用多孔翅片可使换热性能提高134.3%。然而，随着传热的增强，压力损失也增加，这使得多孔翅片的应用变得不可行。因此，通过PEC研究，我们获得了最优设计参数(Da = 10−3,hf = 4 cm, n = 30)，该参数适用于多孔鳍片，传热增强66.38%。
{"title":"Optimizing Effectiveness of Double Pipe Heat Exchanger Using Nanofluid and Different Porous Fins Arrangement","authors":"Avinash Kumar, V. Arya, Chirodeep Bakli","doi":"10.1115/power2021-64248","DOIUrl":"https://doi.org/10.1115/power2021-64248","url":null,"abstract":"\u0000 A numerical study is carried out to investigate the effect of porous fins in counter-flow Double Pipe Heat Exchanger (DPHE). Four DPHE with different porous fin arrangements is simulated for varying Darcy number, fin height, and the number of fins and compared with the conventional DPHE with no porous fins. The Darcy-Brinkman-Forchheimer equation is employed to model the flow in the porous fins considering fixed Re = 100. Al2O3-H2O nanofluid and water are used as hot and cold fluids respectively. Stainless steel is used as porous material with a porosity of 0.65. Results are evaluated in terms of effectiveness and Performance Evaluation Criterion (PEC). The effectiveness of the heat exchanger is used to analyze the heat transfer characteristics whereas the PEC is used to analyze the heat transfer characteristics considering pressure losses also. We evaluated maximum enhancement in thermal performance using effectiveness analysis and through PEC study we evaluated optimal effectiveness and corresponding design parameters. It is shown that utilizing porous fins in DPHE enhances the heat transfer by 134.3%. However, along with enhancement in heat transfer, the pressure losses also enhance which makes the application of porous fin non-viable. Therefore, using the PEC study we obtained optimal design parameters (Da = 10−3, hf = 4 cm, and n = 30) which adapts porous fin viable with enhancement in heat transfer by 66.38%.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"245 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77566704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Onshore/offshore wind turbines play a vital role in addressing the increasing worldwide energy demand. Enhancing the wind power harnessing capability of turbines and extending the life expectancy of their components support further reductions in the final cost of wind energy. Data-driven techniques can complement existing physics-based approaches for complex problems such as wind farm wake modeling. In this paper, a deep learning model is developed to predict the local short-term wind characteristics. A data pre-processing pipeline that includes data cleaning and normalizing steps is developed to generate the training dataset. Time-series forecasting models based on long-short-term-memory (LSTM) and convLSTM are developed and trained for local short-term wind forecasting. The model is validated through experiments on three-year data from the National Renewable Energy Laboratory (NREL) database. The conducted experiments showed favorable performance based on root mean square error (RMSE) and R2 test scores. The R2 values for predicting 1-minute, 30-minute, and 1 hour, wind characteristics for both LSTM and convLSTM were above 0.92. The results are in agreement with the literature. They also demonstrate the effectiveness of the developed models for short-term wind forecasting compared to similar ones.
{"title":"Short-Term Wind Characteristics Forecasting Using Stacked LSTM Networks","authors":"Dorsa Ziaei, N. Goudarzi","doi":"10.1115/power2021-65866","DOIUrl":"https://doi.org/10.1115/power2021-65866","url":null,"abstract":"\u0000 Onshore/offshore wind turbines play a vital role in addressing the increasing worldwide energy demand. Enhancing the wind power harnessing capability of turbines and extending the life expectancy of their components support further reductions in the final cost of wind energy. Data-driven techniques can complement existing physics-based approaches for complex problems such as wind farm wake modeling. In this paper, a deep learning model is developed to predict the local short-term wind characteristics. A data pre-processing pipeline that includes data cleaning and normalizing steps is developed to generate the training dataset. Time-series forecasting models based on long-short-term-memory (LSTM) and convLSTM are developed and trained for local short-term wind forecasting. The model is validated through experiments on three-year data from the National Renewable Energy Laboratory (NREL) database. The conducted experiments showed favorable performance based on root mean square error (RMSE) and R2 test scores. The R2 values for predicting 1-minute, 30-minute, and 1 hour, wind characteristics for both LSTM and convLSTM were above 0.92. The results are in agreement with the literature. They also demonstrate the effectiveness of the developed models for short-term wind forecasting compared to similar ones.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87874252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aanya Singh, Rohit Mandavkar, Sanjay Singh, Raunak Devdatta Prabhu Bhembre, Devansh Jain, D. D. W. Rufuss
Renewable energy, is the primary load bearer of a sustainable circular economy and hydropower being one of the earliest forms of it, has a wide application base. With unprecedented situations being faced by the people every day, power consumption patterns and requirements are changing and so are the faces of the leading economies. However, like other renewable strategies it is assayed based on the greenhouse gas emissions during its operation. This unfortunately presents a true but blurry picture. Some of the long-term issues with creating a dam, are soil quality degradation in downstream regions, loss of aquatic life due to high-speed turbine blades, disbalance in the nutrient cycle of aquatic systems, water contamination with machinery oils, displacement of local communities, loss of soil fertility near the site due to drilling and tunnelling, landslides and seismic issues due to excavation of land which loosens the nearby soil cover. Therefore, our goal is to analyze and compile various case studies of hydro power projects throughout the globe which caused some environmental or social disruption in their respective regions and the various steps that were taken by the government or the locals to tackle these problems. Many areas faced seismic problems, environmental degradation, water profile alterations and social displacement. But, by opting for new turbine technologies, fish friendly channel designs and landscaping procedures featuring indigenous vegetation to restore surrounding ecology, those regions were able to amend the problems with their hydropower project.
{"title":"Socio-Environmental Impacts of Hydro Power Technology- a Review","authors":"Aanya Singh, Rohit Mandavkar, Sanjay Singh, Raunak Devdatta Prabhu Bhembre, Devansh Jain, D. D. W. Rufuss","doi":"10.1115/power2021-64157","DOIUrl":"https://doi.org/10.1115/power2021-64157","url":null,"abstract":"\u0000 Renewable energy, is the primary load bearer of a sustainable circular economy and hydropower being one of the earliest forms of it, has a wide application base. With unprecedented situations being faced by the people every day, power consumption patterns and requirements are changing and so are the faces of the leading economies. However, like other renewable strategies it is assayed based on the greenhouse gas emissions during its operation. This unfortunately presents a true but blurry picture. Some of the long-term issues with creating a dam, are soil quality degradation in downstream regions, loss of aquatic life due to high-speed turbine blades, disbalance in the nutrient cycle of aquatic systems, water contamination with machinery oils, displacement of local communities, loss of soil fertility near the site due to drilling and tunnelling, landslides and seismic issues due to excavation of land which loosens the nearby soil cover. Therefore, our goal is to analyze and compile various case studies of hydro power projects throughout the globe which caused some environmental or social disruption in their respective regions and the various steps that were taken by the government or the locals to tackle these problems. Many areas faced seismic problems, environmental degradation, water profile alterations and social displacement. But, by opting for new turbine technologies, fish friendly channel designs and landscaping procedures featuring indigenous vegetation to restore surrounding ecology, those regions were able to amend the problems with their hydropower project.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"31 11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82750117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The front matter for this proceedings is available by clicking on the PDF icon.
通过点击PDF图标可获得本次会议的主题。
{"title":"POWER2021 Front Matter","authors":"","doi":"10.1115/power2021-fm1","DOIUrl":"https://doi.org/10.1115/power2021-fm1","url":null,"abstract":"\u0000 The front matter for this proceedings is available by clicking on the PDF icon.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75428053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Characteristics of non-premixed flames such as flame height and lift-off height are affected by the presence of magnetic fields due to the paramagnetic properties of some combustion species. However, it is unknown whether magnetic fields can be used to reduce the emission of pollutants in non-premixed flames. In general, pollutant emissions are reduced in combustion systems if the mixing of combustion species is enhanced during the process. Since paramagnetic combustion species such as O2, O, OH, HO2, etc have a preferential motion direction in the presence of magnetic fields, there is a potential to harness this effect of mixing by imposing a magnetic field on the flame. This study seeks to provide some insights on the effect of magnetic field on pollutants generated in a laminar non-premixed flame numerically. The non-premixed flame is simulated using a detailed chemical mechanism for propane-air combustion and a modified Moss-Brookes soot model. To simulate the effect of magnetism on the paramagnetic chemical species, the species paramagnetic susceptibility is computed using the Curie relation. The non-premixed flame is placed at three different locations within the magnetic field. The computation predicted that the amount of average pollutants reduction is dependent on the location of the flames within the magnetic fields with respect to magnetic gradients. The mass weighted average of the soot volume fraction over the computational domain decreased when the non-premixed flame is located at certain locations within the magnetic field of the solenoid with respect to the absence of the magnetic fields, but increases in other locations.
{"title":"Numerical Simulation of the Effect of Magnetic Fields on Soot Formation in Laminar Non-Premixed Flames","authors":"Edison E. Chukwuemeka, I. Schoegl","doi":"10.1115/power2021-64859","DOIUrl":"https://doi.org/10.1115/power2021-64859","url":null,"abstract":"\u0000 Characteristics of non-premixed flames such as flame height and lift-off height are affected by the presence of magnetic fields due to the paramagnetic properties of some combustion species. However, it is unknown whether magnetic fields can be used to reduce the emission of pollutants in non-premixed flames.\u0000 In general, pollutant emissions are reduced in combustion systems if the mixing of combustion species is enhanced during the process. Since paramagnetic combustion species such as O2, O, OH, HO2, etc have a preferential motion direction in the presence of magnetic fields, there is a potential to harness this effect of mixing by imposing a magnetic field on the flame.\u0000 This study seeks to provide some insights on the effect of magnetic field on pollutants generated in a laminar non-premixed flame numerically. The non-premixed flame is simulated using a detailed chemical mechanism for propane-air combustion and a modified Moss-Brookes soot model. To simulate the effect of magnetism on the paramagnetic chemical species, the species paramagnetic susceptibility is computed using the Curie relation. The non-premixed flame is placed at three different locations within the magnetic field.\u0000 The computation predicted that the amount of average pollutants reduction is dependent on the location of the flames within the magnetic fields with respect to magnetic gradients. The mass weighted average of the soot volume fraction over the computational domain decreased when the non-premixed flame is located at certain locations within the magnetic field of the solenoid with respect to the absence of the magnetic fields, but increases in other locations.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"87 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83778575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study focuses on developing and applying an actuator line model (ALM) to predict the wake behind floating offshore wind turbines (FOWTs). A computational method is presented which implements an ALM, able to handle 6 Degree-of-Freedom (DOF) motion dynamics, coupled with a CFD solver. Computational grides used are cubic and do not require a boundary layer mesh. Results show that just about 300k grids are necessary for performance assessment of the NREL Phase VI case. Therefore, the proposed method leads to significantly lower computational cost and easier preprocessing compared to high-order methods used for solving RANS. On the other hand, coupled aerodynamic and motion analyses showed that pitch and surge motions have the most considerable influence on turbine performance due to their inherent effect on 3D local wind inclination in the relative frame. The peak power happened when the platform is in its initial position, where the platform motion velocity is maximum. Finally, it is shown that the wind turbine movement has a considerable effect on its wake characteristics. The gap distances between wake rings can also change wake interactions, and, for the case with platform pitch motion, the condition of the wake is even more complicated as such distance is not the same in all azimuthal sectors. The results show that the applied ALM method is beneficial for simulating the wake behind offshore wind turbines and the complex phenomena in the wake due to platform oscillation.
{"title":"Development of an Actuator Line Model for Simulation of Floating Offshore Wind Turbines","authors":"A. Arabgolarcheh, E. Benini, M. Anbarsooz","doi":"10.1115/power2021-60098","DOIUrl":"https://doi.org/10.1115/power2021-60098","url":null,"abstract":"\u0000 This study focuses on developing and applying an actuator line model (ALM) to predict the wake behind floating offshore wind turbines (FOWTs). A computational method is presented which implements an ALM, able to handle 6 Degree-of-Freedom (DOF) motion dynamics, coupled with a CFD solver. Computational grides used are cubic and do not require a boundary layer mesh. Results show that just about 300k grids are necessary for performance assessment of the NREL Phase VI case. Therefore, the proposed method leads to significantly lower computational cost and easier preprocessing compared to high-order methods used for solving RANS. On the other hand, coupled aerodynamic and motion analyses showed that pitch and surge motions have the most considerable influence on turbine performance due to their inherent effect on 3D local wind inclination in the relative frame. The peak power happened when the platform is in its initial position, where the platform motion velocity is maximum. Finally, it is shown that the wind turbine movement has a considerable effect on its wake characteristics. The gap distances between wake rings can also change wake interactions, and, for the case with platform pitch motion, the condition of the wake is even more complicated as such distance is not the same in all azimuthal sectors. The results show that the applied ALM method is beneficial for simulating the wake behind offshore wind turbines and the complex phenomena in the wake due to platform oscillation.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80766500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a Proportional Integral Derivative (PID) controller design with the presence of an uncertain internal gain and additional time delay in the forward path of a 300 kW Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT). The outputs of the system are turbine speed and the fuel cell mass flow rate. A fixed set of proportional controller coefficients are determined to graphically develop an area of selection for the integral and derivative coefficients of the PID controller. The inputs to the power plant are the electric load and cold air valve. The decentralized controllers are applied to four sub-systems as a Single Input Single Output (SISO). The PID controller coefficients are selected from a singular matrix solution that stabilizes the system and satisfies the internal gain and time delay uncertainties. Two sub-systems are the transfer functions of the turbine speed over the electric load and the cold air valve. The other two sub-systems are the transfer functions of the fuel cell mass flow rate over the electric load and the cold air bypass valve. Multiple options for selecting PID controller coefficients are beneficial to the SOFC-GT plant due to the wide range of operations and internal uncertainty interactions. The specific internal time delay and gain margins increase the reliability and robustness of the SOFC-GT with multiple uncertain parameters.
{"title":"Uncertain Gain and Time-Delay Control of 300-kW SOFC-GT","authors":"T. Emami, D. Tucker, J. Watkins","doi":"10.1115/power2021-64925","DOIUrl":"https://doi.org/10.1115/power2021-64925","url":null,"abstract":"\u0000 This paper presents a Proportional Integral Derivative (PID) controller design with the presence of an uncertain internal gain and additional time delay in the forward path of a 300 kW Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT). The outputs of the system are turbine speed and the fuel cell mass flow rate. A fixed set of proportional controller coefficients are determined to graphically develop an area of selection for the integral and derivative coefficients of the PID controller. The inputs to the power plant are the electric load and cold air valve. The decentralized controllers are applied to four sub-systems as a Single Input Single Output (SISO). The PID controller coefficients are selected from a singular matrix solution that stabilizes the system and satisfies the internal gain and time delay uncertainties. Two sub-systems are the transfer functions of the turbine speed over the electric load and the cold air valve. The other two sub-systems are the transfer functions of the fuel cell mass flow rate over the electric load and the cold air bypass valve. Multiple options for selecting PID controller coefficients are beneficial to the SOFC-GT plant due to the wide range of operations and internal uncertainty interactions. The specific internal time delay and gain margins increase the reliability and robustness of the SOFC-GT with multiple uncertain parameters.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81298876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Within the area of combustion, externally heated microtubes have been introduced to study the combustion characteristics of fuels and fuel blends. Microreactors have advantages over other conventional fuel testing methods because of their potential to test small volumes (< 20 μl) at high throughput. In this work, a high-pressure microreactor is designed and implemented to test fuels up to a pressure of 20 bar where automated testing reduces test time substantially. The novelty of this device is its capability to operate at pressure exceeding the current state of the art of 12 bar. The combustion behavior of fuels is tested in an externally heated quartz tube, with a diameter less than the conventional quenching diameter of the fuel. The ultimate objective of the experiment is to investigate the impact of fuel on flame characteristics. The ability to reach engine relevant pressure conditions and its inherent small volume requirements make this device a potential candidate for measurements of laboratory transportation fuels and fuel blends. For initial validation, tests from an earlier intermediate pressure experiment with ethane/air and nitrogen mixtures are repeated. Chemiluminescence images are taken to evaluate the combustion characteristics in terms of the three classical flame regimes: weak flames, Flames with Repetitive Extinction, and Ignition (FREI) and normal flames. Previous results at intermediate pressure showed that as the pressure increases, the weak flame and FREI regimes shift towards lower velocities. Also, as dilution level increase (i.e. reducing oxygen concentration), the transition from the weak flame to FREI becomes less abrupt and is completely lost for marginal oxygen concentration. The objective of this study is to document flame dynamics at higher pressures.
{"title":"Towards a High-Pressure Microchannel Reactor for Fuel Characterization","authors":"David Akinpelu, I. Schoegl","doi":"10.1115/power2021-64910","DOIUrl":"https://doi.org/10.1115/power2021-64910","url":null,"abstract":"\u0000 Within the area of combustion, externally heated microtubes have been introduced to study the combustion characteristics of fuels and fuel blends. Microreactors have advantages over other conventional fuel testing methods because of their potential to test small volumes (< 20 μl) at high throughput. In this work, a high-pressure microreactor is designed and implemented to test fuels up to a pressure of 20 bar where automated testing reduces test time substantially. The novelty of this device is its capability to operate at pressure exceeding the current state of the art of 12 bar. The combustion behavior of fuels is tested in an externally heated quartz tube, with a diameter less than the conventional quenching diameter of the fuel. The ultimate objective of the experiment is to investigate the impact of fuel on flame characteristics. The ability to reach engine relevant pressure conditions and its inherent small volume requirements make this device a potential candidate for measurements of laboratory transportation fuels and fuel blends. For initial validation, tests from an earlier intermediate pressure experiment with ethane/air and nitrogen mixtures are repeated. Chemiluminescence images are taken to evaluate the combustion characteristics in terms of the three classical flame regimes: weak flames, Flames with Repetitive Extinction, and Ignition (FREI) and normal flames. Previous results at intermediate pressure showed that as the pressure increases, the weak flame and FREI regimes shift towards lower velocities. Also, as dilution level increase (i.e. reducing oxygen concentration), the transition from the weak flame to FREI becomes less abrupt and is completely lost for marginal oxygen concentration. The objective of this study is to document flame dynamics at higher pressures.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89061815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The performance of the propeller is crucial to determine the energy-efficiency of a vessel. Fluid-Structure Interactions (FSI) analysis is one of the widely used methods to determine the hydrodynamic performance of marine propellers. This article is about the validation of a design assessment tool known as ComPropApp which is developed by Cooperative Research Ships (CRS) partners. ComPropApp is a specially designed tool for the FSI analysis of isotropic and composite marine propellers by doing explicit two-way coupling of the BEM-FEM solvers. The Boundary Element Method (BEM) solver of ComPropApp gives it an edge over Reynolds Averaged Navier Stokes Equations (RANSE) solvers in terms of computation time and cost. Hence, it is suitable for the initial design stage. The propeller used in this study is developed under the French Research Project; FabHeli. The validation is done by performing different types of FSI analysis through commercial RANSE solver (STAR-CCM+) and FEM solver (FEMAP) for only one inflow velocity of the open water case which is 10.3 m/s. The fluid solver of ComPropApp (PROCAL) is a Boundary Element Method (BEM) solver that is based on the potential flow theory while the structural solver (TRIDENT) is a FEM solver. The study is divided into four different cases; BEM-FEM one-way coupled FSI analysis, RANSE-FEM one-way coupled FSI analysis, BEM-FEM explicit two-way coupled FSI analysis with ComPropApp and RANSE-FEM implicit two-way coupled FSI analysis with STAR-CCM+. The calculated values of stresses, displacement, and forces from all the methods are compared and the conclusion is drawn.
{"title":"A Comparison of Different Fluid-Structure Interaction Analysis Techniques for the Marine Propeller","authors":"W. Rehman, S. Paboeuf, J. P. Tomy","doi":"10.1115/power2021-64369","DOIUrl":"https://doi.org/10.1115/power2021-64369","url":null,"abstract":"\u0000 The performance of the propeller is crucial to determine the energy-efficiency of a vessel. Fluid-Structure Interactions (FSI) analysis is one of the widely used methods to determine the hydrodynamic performance of marine propellers. This article is about the validation of a design assessment tool known as ComPropApp which is developed by Cooperative Research Ships (CRS) partners. ComPropApp is a specially designed tool for the FSI analysis of isotropic and composite marine propellers by doing explicit two-way coupling of the BEM-FEM solvers. The Boundary Element Method (BEM) solver of ComPropApp gives it an edge over Reynolds Averaged Navier Stokes Equations (RANSE) solvers in terms of computation time and cost. Hence, it is suitable for the initial design stage. The propeller used in this study is developed under the French Research Project; FabHeli.\u0000 The validation is done by performing different types of FSI analysis through commercial RANSE solver (STAR-CCM+) and FEM solver (FEMAP) for only one inflow velocity of the open water case which is 10.3 m/s. The fluid solver of ComPropApp (PROCAL) is a Boundary Element Method (BEM) solver that is based on the potential flow theory while the structural solver (TRIDENT) is a FEM solver. The study is divided into four different cases; BEM-FEM one-way coupled FSI analysis, RANSE-FEM one-way coupled FSI analysis, BEM-FEM explicit two-way coupled FSI analysis with ComPropApp and RANSE-FEM implicit two-way coupled FSI analysis with STAR-CCM+. The calculated values of stresses, displacement, and forces from all the methods are compared and the conclusion is drawn.","PeriodicalId":8567,"journal":{"name":"ASME 2021 Power Conference","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73511004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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