International Journal of Engine Research最新文献

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"title":"Multiple-objective optimization of direct dual fuel stratification (DDFS) combustion at different loads","authors":"Yizi Zhu, Yanzhi Zhang, Zhixia He, Qian Wang, Weimin Li","doi":"10.1177/14680874231204662","DOIUrl":"https://doi.org/10.1177/14680874231204662","url":null,"abstract":"The operating parameters of the direct dual fuel stratification (DDFS) strategy in a heavy-duty engine are optimized across a full load range by utilizing a combination of three-dimensional computational fluid dynamics simulation and genetic algorithm. After obtaining the optimized results, sensitivity analyses were conducted on the operating parameters at various loads using the Pearson method. The results show that the DDFS strategy can attain stable and efficient combustion across the entire full-load range after optimization. At low-to-medium loads, the engine’s performance is predominantly influenced by initial operating parameters, while both initial and injection parameters play critical roles at high loads. The sensitivities of operating parameters increase as load increases, with the operating parameters having higher sensitivities having more concentrated distributions, while those with lower sensitivities have more dispersed distributions. The optimal conditions for low-to-medium load combustion generally involve a premixed-dominated combustion regime with some degree of reactivity stratification, which is strongly influenced by charge thermodynamics. Increasing the proportion of high-reactivity diesel fuel can improve combustion efficiency and stability, particularly under low-load conditions. Under high-load conditions, the optimal combustion strategy involves using a significant amount of direct-injected gasoline to achieve a more distinct stratified and diffusion combustion regime, which helps mitigate excessive heat release rates. However, this approach may result in reduced fuel economy compared to the optimal strategy for low-to-medium loads. As a consequence, the role of charge thermodynamics becomes less significant while the injection strategy becomes more critical for achieving optimal combustion at high loads.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"8 ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139241453","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}

{"title":"Thermal efficiency optimization of a single cylinder gasoline engine based on active jet ignition","authors":"Ziqing Zhao, Y. Qi, Zhi Wang","doi":"10.1177/14680874231208346","DOIUrl":"https://doi.org/10.1177/14680874231208346","url":null,"abstract":"Jet ignition is a promising technology for improving the thermal efficiency of internal combustion engines (ICEs). To achieve the highest possible thermal efficiency, the jet ignition strategy was studied on a gasoline engine. Firstly, a combustion process featuring three stages of heat release, based on uniformly distributed jet ignition, was proposed. Next, the geometric structure of an active jet igniter was optimized using numerical simulations. Using the designed jet igniter, the effects of engine operating conditions were explored, including auxiliary fuel injection in the jet igniter, gross excess air ratio, and engine load and speed, with the goal of maximizing thermal efficiency. A highest indicated thermal efficiency of 50.3% was achieved, verifying the effectiveness of the proposed combustion strategy with uniformly distributed jet ignition. This study provides a technical reference for developing high-efficiency gasoline engines using jet ignition.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"840 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139258230","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}

{"title":"Effects of ammonia energy fractions, diesel injection timings, and loads on combustion and emission characteristics of PFI-DI ammonia-diesel engines","authors":"Can Yang, Zhongxuan Wang, Jianwei Li, Xiaobei Cheng","doi":"10.1177/14680874231207435","DOIUrl":"https://doi.org/10.1177/14680874231207435","url":null,"abstract":"Partially replacing diesel with carbon-free ammonia fuel is gaining more interest in tackling the issue of greenhouse gas emissions in freight transportation applications. But in ammonia-diesel dual-fuel engines, the combustion and emissions are of particular complexity, with complicated trade-offs among the rough combustion, the thermal efficiency, and the CO2/N2O/NO+NO2/NH3 emissions. To this end, this paper conducts systematical experimental tests on a modified PFI-DI single-cylinder heavy-duty diesel engine with ammonia injected in the intake manifold and diesel directly injected into the cylinder, containing ammonia energy fraction ranging from 0% to 50%, engine loads from IMEP 0.5 to 1.3 MPa, and sweeping diesel injection timing. Results show that the heat release of ammonia-diesel dual-fuel combustion (ADDC) possesses two exothermic stages, and as the ammonia energy fraction increases, the heat release process of ADDC in the first stage is intensified and that in the second stage is just the opposite, which causes rougher combustion but lower indicated thermal efficiency (ITE). Increasing the ammonia energy fraction also makes NO+NO2 and CO2 emissions reduced but NH3 and N2O emissions increased. N2O emissions with stronger greenhouse gas impact usually offset the reduction of CO2. Advancing diesel injection timing can improve ITE, but the cost is the rapidly increasing PPRR and NO+NO2 emissions. Besides, as the engine load increases, the ignition delay gets shortened and the combustion process becomes concentrated and efficient, the resistance to ammonia in ADDC gets better, and NH3 emissions are reduced at the cost of more NO+NO2 emissions.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"36 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139274478","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}

{"title":"Three-stage hyperelliptic Kalman filter for health and performance monitoring of aeroengine under multi-source uncertainty","authors":"Ruiqian Sun, Lin-Feng Gou, Zong-Yao Liu, Xiao-Bao Han","doi":"10.1177/14680874231198734","DOIUrl":"https://doi.org/10.1177/14680874231198734","url":null,"abstract":"Aeroengine operation is inevitably subject to multi-source uncertainty, which consists of epistemic uncertainty related to the aeroengine and stochastic uncertainty associated with the control system. This paper presents a solution for health and performance monitoring under multi-source uncertainty to ensure the safety and reliability of aeroengine whole-life operation in complex environments. Based on the hyperelliptic Kalman filter (HeKF), optimal health monitoring is achieved by treating health parameters as the augmented state. Meanwhile, the conservativeness-reduced output prediction is realized with the extra estimation of the unknown state function bias caused by probabilistic system parameters. Considering the computational effort can be significantly reduced by designing a multi-stage filter, the three-stage hyperelliptic Kalman filter (ThSHeKF) is finally developed, achieving high accuracy health parameter estimation and adaptive performance prediction under multi-source uncertainty. Open-loop and closed-loop numerical simulations demonstrate the effectiveness of the proposed ThSHeKF-based health and performance monitoring with high estimation accuracy. Furthermore, compared to the most commonly used extended Kalman filter (EKF), Monte Carlo (MC) experiments shows that the proposed ThSHeKF is less conservative, has better robustness, and is superior in adaptive monitoring under multi-source uncertainty.","PeriodicalId":14034,"journal":{"name":"International Journal of Engine Research","volume":"36 6","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139275636","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}