Pub Date : 2023-01-12DOI: 10.3389/fmech.2022.1090152
S. Gajanayake, S. Bandara, Thusitha Sugathapala
On par with rapid motorization, excessive energy demand and air pollution have become major challenges in the global context. Fuel economy programs and emission reduction targets have proven to be among the most effective in mitigating these issues. In developing successful fuel economy programs and policies, understanding the factors affecting the fuel consumption of road vehicles is essential. Auxiliary engine loads are one of the commonest factors affecting a vehicle’s fuel economy performance. An auxiliary engine load is defined as the energy utilized to operate auxiliary equipment that draws its power from the vehicle’s engine. This study was limited to light duty vehicles, and an analytical method was adopted to assess the fuel economy impact of the auxiliary equipment in terms of air-conditioning load, alternator load, and water pump and steering pump load. As one of the main deliverables, the study developed a novel approach for estimating and modeling the air-conditioning load which is the major auxiliary energy consumer. For an average car of 100 brake horsepower (bhp) (74.7 kW), the engine auxiliary equipment consumes approximately 13.130 kW of power at an engine operating speed of 3,000 RPM, which amounts to 17.6% of the total bhp output. The major contributors to engine power demand are the air-conditioning unit and the alternator, which account for over 97% of the total auxiliary power requirement, while the water-pump and power steering-pump use relatively little power at 3% of the total auxiliary power demand. The novelty of the method adopted during this study is that it theoretically determines the major contributor of the auxiliary power demand, the air-conditioning load, whereas prior reports have used approaches involving empirical methods.
{"title":"A novel approach to estimate power demand of auxiliary engine loads of light duty vehicles","authors":"S. Gajanayake, S. Bandara, Thusitha Sugathapala","doi":"10.3389/fmech.2022.1090152","DOIUrl":"https://doi.org/10.3389/fmech.2022.1090152","url":null,"abstract":"On par with rapid motorization, excessive energy demand and air pollution have become major challenges in the global context. Fuel economy programs and emission reduction targets have proven to be among the most effective in mitigating these issues. In developing successful fuel economy programs and policies, understanding the factors affecting the fuel consumption of road vehicles is essential. Auxiliary engine loads are one of the commonest factors affecting a vehicle’s fuel economy performance. An auxiliary engine load is defined as the energy utilized to operate auxiliary equipment that draws its power from the vehicle’s engine. This study was limited to light duty vehicles, and an analytical method was adopted to assess the fuel economy impact of the auxiliary equipment in terms of air-conditioning load, alternator load, and water pump and steering pump load. As one of the main deliverables, the study developed a novel approach for estimating and modeling the air-conditioning load which is the major auxiliary energy consumer. For an average car of 100 brake horsepower (bhp) (74.7 kW), the engine auxiliary equipment consumes approximately 13.130 kW of power at an engine operating speed of 3,000 RPM, which amounts to 17.6% of the total bhp output. The major contributors to engine power demand are the air-conditioning unit and the alternator, which account for over 97% of the total auxiliary power requirement, while the water-pump and power steering-pump use relatively little power at 3% of the total auxiliary power demand. The novelty of the method adopted during this study is that it theoretically determines the major contributor of the auxiliary power demand, the air-conditioning load, whereas prior reports have used approaches involving empirical methods.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43245102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-12DOI: 10.3389/fmech.2022.998630
M. Kulkarni, S. Dingare, C. Kulkarni
In this paper, the design and development of a solar cycloidal concentrating system along with utilization of the tapered receiver is presented. For the determination of the performance of the system, theoretical analysis was carried out. The novel concept of utilizing a tapered receiver for a solar cycloidal concentrating system is an innovative approach for this research. After the determination of various parameters for this system, a patent was filed and published under the patent No. 202021028009A on 31 July 2020. For the comparative study purpose, the author has taken three receivers with a constant concentration ratio and different diameters such as .038 m, .031 m, and .025 m. Theoretical evaluation of the system is estimated using modes of heat transfers and using the relation of energy balance. Various correlations are determined for an analytical evaluation purpose. By using graphical collation of all the results for all the three receivers, the author has proposed to use a tapered receiver with the variable CR. CR denotes the concentration ratio. A concentration ratio is defined as the ratio of the area of an aperture to the area of a receiver. In this research, a variable concentration ratio (CR) is used. The receiver used has a diameter which reduces from the inlet to the outlet, and hence, the intercept factor decreases and the concentration ratio increases, leading to an enhancement in efficiency.
{"title":"Design and development of the solar cycloidal thermal concentrator and tapered receiver assembly along with theoretical evaluation of system performance","authors":"M. Kulkarni, S. Dingare, C. Kulkarni","doi":"10.3389/fmech.2022.998630","DOIUrl":"https://doi.org/10.3389/fmech.2022.998630","url":null,"abstract":"In this paper, the design and development of a solar cycloidal concentrating system along with utilization of the tapered receiver is presented. For the determination of the performance of the system, theoretical analysis was carried out. The novel concept of utilizing a tapered receiver for a solar cycloidal concentrating system is an innovative approach for this research. After the determination of various parameters for this system, a patent was filed and published under the patent No. 202021028009A on 31 July 2020. For the comparative study purpose, the author has taken three receivers with a constant concentration ratio and different diameters such as .038 m, .031 m, and .025 m. Theoretical evaluation of the system is estimated using modes of heat transfers and using the relation of energy balance. Various correlations are determined for an analytical evaluation purpose. By using graphical collation of all the results for all the three receivers, the author has proposed to use a tapered receiver with the variable CR. CR denotes the concentration ratio. A concentration ratio is defined as the ratio of the area of an aperture to the area of a receiver. In this research, a variable concentration ratio (CR) is used. The receiver used has a diameter which reduces from the inlet to the outlet, and hence, the intercept factor decreases and the concentration ratio increases, leading to an enhancement in efficiency.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44064341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-12DOI: 10.3389/fmech.2022.1022570
Bryan Zavala, J. McCarthy, T. Harris
Commercial vehicles require fast aftertreatment heat-up to move the SCR catalyst into the most efficient temperature range to meet upcoming NOX regulations while minimizing CO2. One solution to this challenge is to add a fuel burner upstream of the con`ventional heavy-duty diesel aftertreatment system. The focus of this paper is to optimize a burner based thermal management approach. The objective included complying with CARB’s 2027 low NOX emissions standards for on-road heavy duty diesel engines. This was accomplished by pairing the burner system with cylinder de-activation on the engine and/or a light-off SCR sub-system. A system solution is demonstrated using a heavy-duty diesel engine with an aged aftertreatment system targeted for 2027 emission levels using various levels of controls. The baseline layer of controls includes cylinder deactivation to raise the exhaust temperature more than 100°C in combination with elevated idle speed to increase the mass flowrate through the aftertreatment system. The combination of operating the fuel burner, cylinder deactivation and elevated idle speed (during cold start) allows the aftertreatment system to heat up in a small fraction of the time demonstrated by today’s systems. Performance was quantified over the cold FTP, hot FTP, low load cycle (LLC) and the U.S. beverage cycle. The improvement in NOX reduction and the CO2 savings over these cycles are highlighted.
{"title":"Burner based thermal management approach utilizing in-exhaust burner technology with a CDA equipped engine","authors":"Bryan Zavala, J. McCarthy, T. Harris","doi":"10.3389/fmech.2022.1022570","DOIUrl":"https://doi.org/10.3389/fmech.2022.1022570","url":null,"abstract":"Commercial vehicles require fast aftertreatment heat-up to move the SCR catalyst into the most efficient temperature range to meet upcoming NOX regulations while minimizing CO2. One solution to this challenge is to add a fuel burner upstream of the con`ventional heavy-duty diesel aftertreatment system. The focus of this paper is to optimize a burner based thermal management approach. The objective included complying with CARB’s 2027 low NOX emissions standards for on-road heavy duty diesel engines. This was accomplished by pairing the burner system with cylinder de-activation on the engine and/or a light-off SCR sub-system. A system solution is demonstrated using a heavy-duty diesel engine with an aged aftertreatment system targeted for 2027 emission levels using various levels of controls. The baseline layer of controls includes cylinder deactivation to raise the exhaust temperature more than 100°C in combination with elevated idle speed to increase the mass flowrate through the aftertreatment system. The combination of operating the fuel burner, cylinder deactivation and elevated idle speed (during cold start) allows the aftertreatment system to heat up in a small fraction of the time demonstrated by today’s systems. Performance was quantified over the cold FTP, hot FTP, low load cycle (LLC) and the U.S. beverage cycle. The improvement in NOX reduction and the CO2 savings over these cycles are highlighted.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":"8 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41571115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-09DOI: 10.3389/fmech.2022.1075795
Raffaele Ranzani, Martin Albrecht, C. Haarman, E. Koh, Giada Devittori, J. Held, Frederik J. Tönis, R. Gassert, O. Lambercy
Introduction: There is evidence that increasing therapy dose after stroke might promote recovery. Unfortunately, in clinical practice, therapy dose is limited by financial and organizational constraints. Simple robotic devices could be used without supervision in the clinic or at home to increase dose without requiring additional resources. For this purpose, we developed HandyBot, a portable three-degrees-of-freedom end-effector haptic device to perform sensorimotor task-oriented therapy of hand function (i.e., grasping, forearm pronosupination, wrist flexion-extension) in different environments. Methods: We present the mechatronic design of the device and its technical evaluation in terms of workspace, dynamics (i.e., max end-effector velocity, acceleration and force), sensing (i.e., position, velocity and force resolution) and haptic performance (i.e., transparency, maximum stable impedance range, rigid contact rendering accuracy). In addition, its feasibility and usability (in terms of System Usability Scale (SUS)) were assessed in a single-session experiment with four subjects with chronic stroke that tested the HandyBot therapy platform (i.e., haptic device with a graphical/physical user interface and a set of therapy exercises) while simulating unsupervised use (i.e., the subject used the device independently while a therapist was only observing the session). Results: HandyBot showed hardware and control performances comparable to other less portable therapy devices for hand function (e.g., 94% accuracy in stiffness rendering, low apparent mass of 0.2 kg in transparency mode), making it a suitable platform for the implementation of sensorimotor therapy exercises. HandyBot showed good platform usability in terms of SUS (i.e., above 75 out of 100 for device and graphical user interfaces, above 65 out of 100 for the exercises) when tested in simulated unsupervised settings. These tests underlined minor design improvements that should be considered to allow using such a device in uncontrolled settings. Discussion: HandyBot is a novel robot for hand rehabilitation after stroke that revealed high-quality hardware and haptic performance. HandyBot was usable for stroke patients at first exposure for (simulated) unsupervised robot-assisted sensorimotor therapy of hand function. This therapy approach combined with this novel portable robotic device has the potential to help increase therapy dose and decrease therapy-associated costs (e.g., therapist time to therapy time ratio) in different environments.
{"title":"Design, characterization and preliminary usability testing of a portable robot for unsupervised therapy of hand function","authors":"Raffaele Ranzani, Martin Albrecht, C. Haarman, E. Koh, Giada Devittori, J. Held, Frederik J. Tönis, R. Gassert, O. Lambercy","doi":"10.3389/fmech.2022.1075795","DOIUrl":"https://doi.org/10.3389/fmech.2022.1075795","url":null,"abstract":"Introduction: There is evidence that increasing therapy dose after stroke might promote recovery. Unfortunately, in clinical practice, therapy dose is limited by financial and organizational constraints. Simple robotic devices could be used without supervision in the clinic or at home to increase dose without requiring additional resources. For this purpose, we developed HandyBot, a portable three-degrees-of-freedom end-effector haptic device to perform sensorimotor task-oriented therapy of hand function (i.e., grasping, forearm pronosupination, wrist flexion-extension) in different environments. Methods: We present the mechatronic design of the device and its technical evaluation in terms of workspace, dynamics (i.e., max end-effector velocity, acceleration and force), sensing (i.e., position, velocity and force resolution) and haptic performance (i.e., transparency, maximum stable impedance range, rigid contact rendering accuracy). In addition, its feasibility and usability (in terms of System Usability Scale (SUS)) were assessed in a single-session experiment with four subjects with chronic stroke that tested the HandyBot therapy platform (i.e., haptic device with a graphical/physical user interface and a set of therapy exercises) while simulating unsupervised use (i.e., the subject used the device independently while a therapist was only observing the session). Results: HandyBot showed hardware and control performances comparable to other less portable therapy devices for hand function (e.g., 94% accuracy in stiffness rendering, low apparent mass of 0.2 kg in transparency mode), making it a suitable platform for the implementation of sensorimotor therapy exercises. HandyBot showed good platform usability in terms of SUS (i.e., above 75 out of 100 for device and graphical user interfaces, above 65 out of 100 for the exercises) when tested in simulated unsupervised settings. These tests underlined minor design improvements that should be considered to allow using such a device in uncontrolled settings. Discussion: HandyBot is a novel robot for hand rehabilitation after stroke that revealed high-quality hardware and haptic performance. HandyBot was usable for stroke patients at first exposure for (simulated) unsupervised robot-assisted sensorimotor therapy of hand function. This therapy approach combined with this novel portable robotic device has the potential to help increase therapy dose and decrease therapy-associated costs (e.g., therapist time to therapy time ratio) in different environments.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46459000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-09DOI: 10.3389/fmech.2022.1081659
W. Elhelew, A. Abdelmaqsoud, Khaleed Faran ElBagoury, H. A. Shanan
Energy is regarded as one of the most crucial resources in the industrial process. Numerous measurements were made in the year 2021 in the workshops of the Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Egypt, using a gasoline engine (single cylinder with air-cooling) that was used to power an irrigation pump with a discharge diameter of 2 inches, which was manufactured in Egypt. To combine natural gas and air before entering the engine, a variety of mixers were created. Four different types of mixers were employed with iron pipes of various sizes: 90° angle T-mixer (T90), 45° angle T-mixer (T45), 30° angle T-mixer (T30), and venture mixer (VM). The engine shift speeds were set at 1,750, 2,300, 2,900, and 3,500 rpm. The water pump was powered by natural gas and gasoline. The findings in this study focused on the evaluation of technical indicators for several types of mixers that combine natural gas and air to power an irrigation pump, where the actual power (braking power) is superior to all types while operating with gasoline (3.07 kW). A commensurability on every side the report of on the up steam, in the mixer type (T45) (2.83 kW) was 7.8% about than gasoline. The lowest specific fuel consumption (S.fc) for gasoline was 219.025 gm/Kw.h at an engine speed of 2,900 rpm. The T45 mixer had the lowest S.fc of 234.612 gm/KW.h, compared with other types of mixers at an engine speed of 2,900 rpm, an increase of 6.6% compared with gasoline. The T45 mixer had the highest pump discharge of 528.133 L/min, an increase of 2.1% compared with gasoline. Compared with other types of T-mixers, the T45 mixer had the highest actual hydraulic power of 0.6 kW, which was 10.5% lower than that of gasoline. As for the economic indicators, the T90 mixer had the lowest net present value (NPV) of 77219.5, and the T45 mixer had the highest NPV of 106900.7. The mixer-type VM had the lowest benefit–cost ratio (B/C) of 1.38, and the T45mixer had the highest B/C of 1.54.
{"title":"Technical and economic evaluation of an engine and irrigation pump using a T-type mixer for natural gas","authors":"W. Elhelew, A. Abdelmaqsoud, Khaleed Faran ElBagoury, H. A. Shanan","doi":"10.3389/fmech.2022.1081659","DOIUrl":"https://doi.org/10.3389/fmech.2022.1081659","url":null,"abstract":"Energy is regarded as one of the most crucial resources in the industrial process. Numerous measurements were made in the year 2021 in the workshops of the Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Egypt, using a gasoline engine (single cylinder with air-cooling) that was used to power an irrigation pump with a discharge diameter of 2 inches, which was manufactured in Egypt. To combine natural gas and air before entering the engine, a variety of mixers were created. Four different types of mixers were employed with iron pipes of various sizes: 90° angle T-mixer (T90), 45° angle T-mixer (T45), 30° angle T-mixer (T30), and venture mixer (VM). The engine shift speeds were set at 1,750, 2,300, 2,900, and 3,500 rpm. The water pump was powered by natural gas and gasoline. The findings in this study focused on the evaluation of technical indicators for several types of mixers that combine natural gas and air to power an irrigation pump, where the actual power (braking power) is superior to all types while operating with gasoline (3.07 kW). A commensurability on every side the report of on the up steam, in the mixer type (T45) (2.83 kW) was 7.8% about than gasoline. The lowest specific fuel consumption (S.fc) for gasoline was 219.025 gm/Kw.h at an engine speed of 2,900 rpm. The T45 mixer had the lowest S.fc of 234.612 gm/KW.h, compared with other types of mixers at an engine speed of 2,900 rpm, an increase of 6.6% compared with gasoline. The T45 mixer had the highest pump discharge of 528.133 L/min, an increase of 2.1% compared with gasoline. Compared with other types of T-mixers, the T45 mixer had the highest actual hydraulic power of 0.6 kW, which was 10.5% lower than that of gasoline. As for the economic indicators, the T90 mixer had the lowest net present value (NPV) of 77219.5, and the T45 mixer had the highest NPV of 106900.7. The mixer-type VM had the lowest benefit–cost ratio (B/C) of 1.38, and the T45mixer had the highest B/C of 1.54.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49323368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-09DOI: 10.3389/fmech.2022.973293
Hao Zhang, J. Gou, Peng Yin, Xinrong Su, Xin Yuan
The flow in the turbine endwall region consists of the complicated secondary flow structures driven by the lateral pressure gradient, which heavily affects the performance of film cooling. In this work, the film-cooling hole design optimization is performed considering the existence of the lateral pressure gradient in the real flow environment. Results have shown that the optimal film-cooling hole design is heavily influenced by the lateral pressure gradient in the endwall region, especially the compound angle design is clearly different from the flat plate flow environment. The optimization results are further validated with experiments using the pressure-sensitive paint (PSP) technique, and the film cooling performance is shown to be improved by 42.9%. This work demonstrates the importance of considering the real flow environment in the film-cooling hole design and also can provide guidance to the film-cooling hole design in the endwall region.
{"title":"Film-cooling hole optimization and experimental validation considering the lateral pressure gradient","authors":"Hao Zhang, J. Gou, Peng Yin, Xinrong Su, Xin Yuan","doi":"10.3389/fmech.2022.973293","DOIUrl":"https://doi.org/10.3389/fmech.2022.973293","url":null,"abstract":"The flow in the turbine endwall region consists of the complicated secondary flow structures driven by the lateral pressure gradient, which heavily affects the performance of film cooling. In this work, the film-cooling hole design optimization is performed considering the existence of the lateral pressure gradient in the real flow environment. Results have shown that the optimal film-cooling hole design is heavily influenced by the lateral pressure gradient in the endwall region, especially the compound angle design is clearly different from the flat plate flow environment. The optimization results are further validated with experiments using the pressure-sensitive paint (PSP) technique, and the film cooling performance is shown to be improved by 42.9%. This work demonstrates the importance of considering the real flow environment in the film-cooling hole design and also can provide guidance to the film-cooling hole design in the endwall region.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45082209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-05DOI: 10.3389/fmech.2022.924755
Leiyong Jiang, P. Trembath, P. Patnaik, M. Capurro
The aircraft engine hot section is most vulnerable and failure prone to environmental particle ingestion, which, particularly for helicopters, can cause detrimental effects ranging from reduced performance to complete engine failure. The objective of this work is to develop an analytical tool to assess environmental particle impact on engine hot sections. The current state of the art in experimental and analytical research on environmental particle ingestion related to engine hot sections was reviewed, with emphasis on sand particles. From these efforts, the available experimental data for model calibration were identified, and an innovative particle rebound/deposition model has been developed. A semi-empirical approach is selected to model particles bouncing off metal surfaces, where the coefficients of restitution measured in a temperature range of 297–1323 K are used to calculate particle bounce-back velocity components. The developed deposition model is based on non-dimensional parameter analysis over more than seventy experiments related to particle deposition in engine hot sections. The metal surface temperature, one of two critical parameters in particle deposition, is also included in the model. The model was successfully implemented into commercial software and checked step by step. It was calibrated by two cases: sand [Arizona road dust (ARD)] particle impingement on a circular plate and Mt. St. Helens volcanic ash impinging on a first-stage air-cooled nozzle guide vane (NGV). For the former case, the calibrated model predicts fairly well the variation of particle deposition rate with flow/particle temperature. The latter case indicates that the particle deposition rate at engine operating conditions can be assessed by the developed model. Due to the lack of experimental data that would permit a full calibration/validation, for the time being the model can be only used under limited conditions. As additional relevant experimental data appears, the model will be continuously improved.
{"title":"Environmental particle rebound/deposition modeling in engine hot sections","authors":"Leiyong Jiang, P. Trembath, P. Patnaik, M. Capurro","doi":"10.3389/fmech.2022.924755","DOIUrl":"https://doi.org/10.3389/fmech.2022.924755","url":null,"abstract":"The aircraft engine hot section is most vulnerable and failure prone to environmental particle ingestion, which, particularly for helicopters, can cause detrimental effects ranging from reduced performance to complete engine failure. The objective of this work is to develop an analytical tool to assess environmental particle impact on engine hot sections. The current state of the art in experimental and analytical research on environmental particle ingestion related to engine hot sections was reviewed, with emphasis on sand particles. From these efforts, the available experimental data for model calibration were identified, and an innovative particle rebound/deposition model has been developed. A semi-empirical approach is selected to model particles bouncing off metal surfaces, where the coefficients of restitution measured in a temperature range of 297–1323 K are used to calculate particle bounce-back velocity components. The developed deposition model is based on non-dimensional parameter analysis over more than seventy experiments related to particle deposition in engine hot sections. The metal surface temperature, one of two critical parameters in particle deposition, is also included in the model. The model was successfully implemented into commercial software and checked step by step. It was calibrated by two cases: sand [Arizona road dust (ARD)] particle impingement on a circular plate and Mt. St. Helens volcanic ash impinging on a first-stage air-cooled nozzle guide vane (NGV). For the former case, the calibrated model predicts fairly well the variation of particle deposition rate with flow/particle temperature. The latter case indicates that the particle deposition rate at engine operating conditions can be assessed by the developed model. Due to the lack of experimental data that would permit a full calibration/validation, for the time being the model can be only used under limited conditions. As additional relevant experimental data appears, the model will be continuously improved.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42428862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-04DOI: 10.3389/fmech.2022.1086124
Yumin Zhang, Xigui Wang, Yongmei Wang
The expected preloading effect of a hydraulic press frame parts (upper/lower semi-circular beams and columns) with pre-stressed by means of Winding Steel Wires which is directly related to the reliability and normal safe operation of the hydraulic press. The deformation of the Hydraulic Press Column (HPC) is an important indicator of the optimal preloading effect of the hydraulic press. A novelty of this project is to break through a bottleneck technology, the continuous cumulative deformation of a Hydraulic Press Column under seven time-varying steps is critical issues especially in theoretically calculated for a 20 MN double-frame hydraulic press with pre-stressed using WAW. A solid model with a pre-stressed frame is pre-designed by 3D software, and two simulation methods, equivalent pressure loading and equivalent temperature loading, are used to simulate and analyze the continuous cumulative deformation of the HPC under each step in Ansys Workbench software. By comparing the deformation and error analysis in the three cases above, the feasibility of the two simulation methods is verified, which leads to the advantages and disadvantages of each method in order to guide the subsequent design.
{"title":"Numerical calculation of a 20MN heavy duty hydraulic press for analyzing the double frame pre-stressed steel wire winding","authors":"Yumin Zhang, Xigui Wang, Yongmei Wang","doi":"10.3389/fmech.2022.1086124","DOIUrl":"https://doi.org/10.3389/fmech.2022.1086124","url":null,"abstract":"The expected preloading effect of a hydraulic press frame parts (upper/lower semi-circular beams and columns) with pre-stressed by means of Winding Steel Wires which is directly related to the reliability and normal safe operation of the hydraulic press. The deformation of the Hydraulic Press Column (HPC) is an important indicator of the optimal preloading effect of the hydraulic press. A novelty of this project is to break through a bottleneck technology, the continuous cumulative deformation of a Hydraulic Press Column under seven time-varying steps is critical issues especially in theoretically calculated for a 20 MN double-frame hydraulic press with pre-stressed using WAW. A solid model with a pre-stressed frame is pre-designed by 3D software, and two simulation methods, equivalent pressure loading and equivalent temperature loading, are used to simulate and analyze the continuous cumulative deformation of the HPC under each step in Ansys Workbench software. By comparing the deformation and error analysis in the three cases above, the feasibility of the two simulation methods is verified, which leads to the advantages and disadvantages of each method in order to guide the subsequent design.","PeriodicalId":48635,"journal":{"name":"Frontiers of Mechanical Engineering","volume":" ","pages":""},"PeriodicalIF":4.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47694369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2023-01-04DOI: 10.3389/fmech.2022.1072214
S. Manzello, Sayaka Suzuki
Large outdoor fires have become commonplace all over the world. The International Organization for Standardization (ISO) defines large outdoor fires as an urban fire, tsunami-generated fire, volcano-generated fire, wildland-urban interface (WUI) fire, wildland fire, or informal settlement fire, where the total burnout area is significant. Perhaps of all the large outdoor fires, it is wildland fires that spread into urban areas, simply called WUI fires that attract the most attention. A glance at the recent headlines in the summer of 2022 reveals numerous catastrophic WUI fires all over Europe. Across the Atlantic Ocean in the USA, there is yet another destructive WUI fire raging in the USA state of California. With the increasing risks from a changing climate, these large outdoor fire disasters are only going to become more and more commonplace all over the world. More homes will be lost and more lives will be lost. It is the authors opinion that a targeted, multi-disciplinary approach is needed to address the large outdoor fire problem. In this short, invited paper to Horizons in Mechanical Engineering, it is argued that large outdoor fire problem is a fascinating and challenging research area and that engineers have the necessary skills and training to impact a problem that influences millions upon millions of people all over the world. An important danger, present in all large outdoor fires, are firebrands. Firebrands are introduced for non-specialist readers, and the most recent literature is reviewed. Several challenges are discussed, in particular, areas where engineers may help move the needle forward on this globally important topic.
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