title={The effects of boost pressure on stratification and burn duration of gasoline homogeneous charge compression ignition combustion},
author={Shingne, Prasad S and Middleton, Robert J and Borgnakke, Claus and Martz, Jason B},
journal={International Journal of Engine Research},
volume={20},
number={3},
pages={359–377 },
year={2018},
category={journal},
doi={10.1177/1468087417754177},
publisher={SAGE Publications Sage UK: London, England}
abstract={This article investigates the effects of intake pressure (boost) on the pre-ignition stratification and burn duration of homogeneous charge compression ignition combustion. Full cycle computational fluid dynamics simulations are performed with gasoline kinetics. An intake pressure sweep is performed while maintaining the same combustion timing and mean composition. The burn duration reduces with increasing boost, even though intake temperature is reduced to hold combustion timing constant. It is shown that the compositional stratification increases with boost whereas thermal stratification decreases. A quasi-dimensional model is employed to assess the effect of compositional stratification, pressure, mean temperature and isolate the effect of thermal stratification on burn duration. The analysis reveals that reducing charge temperature neutralizes the effect of increased boost on reactivity and the shorter burn durations at higher boost are primarily due to the lower thermal stratification. It is shown that higher pressures do not significantly increase the mixing and the lower thermal stratification is due to lower wall heat losses per unit charge mass. A follow-up set of non-reacting simulations with adiabatic walls corroborate this claim by revealing a constant magnitude of thermal stratification across the boost sweep.}
}
title={Thermodynamic model for homogeneous charge compression ignition combustion with recompression valve events and direct injection: Part II—combustion model and evaluation against transient experiments},
author={Shingne, Prasad S and Sterniak, Jeff and Assanis, Dennis N and Borgnakke, Claus and Martz, Jason B},
journal={International Journal of Engine Research},
volume={18},
number={7},
pages={677--700},
year={2017},
category={journal},
doi={10.1177/1468087416665052},
publisher={SAGE Publications Sage UK: London, England}
abstract={This two-part article presents a combustion model for boosted and moderately stratified homogeneous charge compression ignition combustion for use in thermodynamic engine cycle simulations. The model consists of two parts: one an ignition model for the prediction of auto-ignition onset and the other an empirical combustion rate model. This article focuses on the development of the combustion model which is algebraic in form and is based on the key physical variables affecting the combustion process. The model is fit with experimental data collected from 290 discrete automotive homogeneous charge compression ignition operating conditions with moderate stratification resulting from both the direct injection and negative valve overlap valve events. Both the ignition model from part 1 and the combustion model from this article are implemented in GT-Power and validated against experimental homogeneous charge compression ignition data under steady-state and transient conditions. The ignition and combustion model are then exercised to identify the dominant variables affecting the homogeneous charge compression ignition and combustion processes. Sensitivity analysis reveals that ignition timing is primarily a function of the charge temperature, and that combustion duration is largely a function of ignition timing.}
}
title={A Thermodynamic model for homogeneous charge compression ignition combustion with recompression valve events and direct injection: Part I -- Adiabatic core ignition model},
author={Shingne, Prasad S and Middleton, Robert J and Assanis, Dennis N and Borgnakke, Claus and Martz, Jason B},
journal={International Journal of Engine Research},
volume={18},
number={7},
pages={657--676},
year={2017},
category={journal},
doi={10.1177/1468087416664635},
publisher={SAGE Publications Sage UK: London, England}
abstract={This two-part article presents a model for boosted and moderately stratified homogeneous charge compression ignition combustion for use in thermodynamic engine cycle simulations. The model consists of two components: one an ignition model for the prediction of auto-ignition onset and the other an empirical combustion rate model. This article focuses on the development and validation of the homogeneous charge compression ignition model for use under a broad range of operating conditions. Using computational fluid dynamics simulations of the negative valve overlap valve events typical of homogeneous charge compression ignition operation, it is shown that there is no noticeable reaction progress from low-temperature heat release, and that ignition is within the high-temperature regime (T > 1000 K), starting within the highest temperature cells of the computational fluid dynamics domain. Additional parametric sweeps from the computational fluid dynamics simulations, including sweeps of speed, load, intake manifold pressures and temperature, dilution level and valve and direct injection timings, showed that the assumption of a homogeneous charge (equivalence ratio and residuals) is appropriate for ignition modelling under the conditions studied, considering the strong sensitivity of ignition timing to temperature and its weak compositional dependence. Use of the adiabatic core temperature predicted from the adiabatic core model resulted in temperatures within \pm 1% of the peak temperatures of the computational fluid
dynamics domain near the time of ignition. Thus, the adiabatic core temperature can be used within an auto-ignition integral as a simple and effective method for estimating the onset of homogeneous charge compression ignition autoignition. The ignition model is then validated with an experimental 92.6 anti-knock index gasoline-fuelled homogeneous
charge compression ignition dataset consisting of 290 data points covering a wide range of operating conditions. The tuned ignition model predictions of \theta_{50} have a root mean square error of 1.7 ^{\circ} crank angle and R^2 = 0.63 compared to the experiments.}
}
title={A low-order adaptive engine model for SI--HCCI mode transition control applications with cam switching strategies},
author={Gorzelic, Patrick and Shingne, Prasad and Martz, Jason and Stefanopoulou, Anna and Sterniak, Jeff and Jiang, Li},
journal={International Journal of Engine Research},
volume={17},
number={4},
pages={451--468},
year={2016},
category={journal},
doi={10.1177/1468087415585016},
publisher={SAGE Publications Sage UK: London, England}
abstract={This article presents a low-order engine model to support model-based control development for mode transitions between spark ignition (SI) and homogeneous charge compression ignition (HCCI) combustion modes in gasoline engines. The modeling methodology focuses on cam switching mode transition strategies wherein the mode is abruptly changed between SI and recompression HCCI via a switch of the cam lift and phasing. The model is parameterized to a wide range of steady-state data which are selected to include conditions pertinent to cam switching mode transitions. An additional HCCI combustion model parameter is augmented and tuned based on transient data from SI to HCCI mode transitions where the conditions can be significantly outside any contained in the baseline steady-state parameterization. An adaptation routine is given which allows transient data be assimilated in online operation to update the augmented parameter and improve SI–HCCI transition predictions. With the baseline steady-state parameterization and augmented mode transition parameter, the model is shown to reproduce both steady-state data and transient performance output time histories from SI–HCCI transitions with considerable accuracy.}
}
title={A Comparison of Valving Strategies Appropriate for Multimode Combustion Within a Downsized Boosted Automotive Engine—Part II: Mid Load Operation Within the SACI Combustion Regime},
author={Gerow, Matthew S and Shingne, Prasad S and Triantopoulos, Vassilis and Bohac, Stanislav V and Martz, Jason B},
journal={Journal of Engineering for Gas Turbines and Power},
volume={136},
number={10},
pages={101508-101508-11},
year={2014},
category={journal},
doi={10.1115/1.4027360},
publisher={American Society of Mechanical Engineers}
abstract={Spark assisted compression ignition (SACI) is a combustion mode that may offer significant efficiency improvements compared to conventional spark-ignited combustion systems. Unfortunately, SACI is constrained to a relatively narrow range of dilution levels and top dead center temperatures. Both positive valve overlap (PVO) and negative valve overlap (NVO) strategies may be utilized to attain these conditions at low and intermediate engine loads. The current work compares 1D thermodynamic simulations of PVO valving strategies and a baseline NVO strategy in a downsized boosted automotive engine with variable valve timing capability. As future downsized boosted engines may employ multiple combustion modes, the goal of this work is the definition of valving strategies appropriate for SACI combustion at low to moderate loads and spark ignition (SI) combustion at moderate to high loads for an engine with fixed camshaft profiles. PVO durations, valve opening timings, and peak lifts are investigated at low to moderate loads and are compared to a baseline NVO configuration in order to assess valving strategies appropriate for multimode combustion operation. A valvetrain kinematic model is used to translate the desired valve lift profiles into camshaft profiles while a kinematic analysis is used to calculate piston to valve clearances and to define the practical limits of the PVO strategies. The NVO and PVO strategies are also compared to throttled SI operation at part load to assess the overall efficiency benefit of operating under the thermodynamic conditions of the SACI combustion regime. While the results of this study are engine specific, there are several camshaft profiles that are appropriate for the use of PVO rebreathing type valve events. For the range of PVO valve events examined and taking into consideration piston to valve interference, the use of high exhaust and low intake lifts with early exhaust valve opening timing and long PVO durations enables high levels of internal exhaust gas recirculation (EGR) with relatively low pumping losses.}
}
title={A Comparison of Valving Strategies Appropriate For Multimode Combustion Within a Downsized Boosted Automotive Engine—Part I: High Load Operation Within the Spark Ignition Combustion Regime},
author={Shingne, Prasad S and Gerow, Matthew S and Triantopoulos, Vassilis and Bohac, Stanislav V and Martz, Jason B},
journal={Journal of Engineering for Gas Turbines and Power},
volume={136},
number={10},
pages={101507-101507-10},
year={2014},
category={journal},
doi={10.1115/1.4027359},
publisher={American Society of Mechanical Engineers}
abstract={As future downsized boosted engines may employ multiple combustion modes, the goal of the current work is the definition of valving strategies appropriate for moderate to high load spark ignition (SI) combustion and at low to moderate loads for spark assisted compression ignition (SACI) combustion for an engine with variable valve timing capability and fixed camshaft profiles. The dilution and unburned gas temperature requirements for SACI combustion can be markedly different from those of SI; therefore it is important to ensure that a given valving strategy is appropriate for operation within both regimes. This paper compares one-dimensional (1D) thermodynamic simulations of rated engine operation with positive valve overlap (PVO) and a baseline negative valve overlap (NVO) camshaft design in a boosted automotive engine with variable valve timing capability. Several peak lifts and valve open durations are investigated to guide the down-selection of camshaft profiles for further evaluation under SACI conditions in a companion paper. While the results of this study are engine specific, rated performance predictions show that the duration of both the intake and exhaust camshafts significantly impacts the ability to achieve high load operation. While it was noted that the flow through the exhaust valves chokes for the majority of the exhaust stroke for peak exhaust lifts less than 8 mm, the aggressive engine rating of 194 kW at 5250 rpm could be achieved with peak intake lifts as low as 4 mm and baseline duration. Therefore, camshafts with peak lifts of 8/4 mm exhaust/intake were down-selected to facilitate multimode combustion operation with high levels of PVO. Analysis of high load operation with the down-selected camshafts indicates that peak unburned gas temperatures remain low enough to mitigate end-gas knock, while other variables such as peak cylinder pressure, turbine inlet temperature, and turbocharger speed are all predicted to be within acceptable limits.}
}
title={A low-order HCCI model extended to capture SI-HCCI mode transition data with two-stage cam switching},
author={Gorzelic, Patrick and Shingne, Prasad and Martz, Jason and Stefanopoulou, Anna and Sterniak, Jeff and Jiang, Li},
booktitle={Proc. ASME 2014 Dynamic Systems and Control Conference},
address={San Antonio, Texas, USA},
doi={10.1115/DSCC2014-6275},
pages={V002T34A005--V002T34A005},
year={2014},
category={conference}
abstract={A low-order homogeneous charge compression ignition (HCCI) combustion model to support model-based control development for spark ignition (SI)/HCCI mode transitions is presented. Emphasis is placed on mode transition strategies wherein SI combustion is abruptly switched to recompression HCCI combustion through a change of the cam lift and opening of the throttle, as is often employed in studies utilizing two-stage cam switching devices. The model is parameterized to a steady-state dataset which considers throttled operation and significant air-fuel ratio variation, which are pertinent conditions to two-stage cam switching mode transition strategies. Inspection and simulation of transient SI to HCCI (SI-HCCI) mode transition data shows that the extreme conditions present when switching from SI to HCCI can cause significant prediction error in the combustion performance outputs even with the model’s adequate steady-state fit. When a correction factor related to residual gas temperature is introduced to account for these extreme conditions, it is shown that the model reproduces transient performance output time histories in SI-HCCI mode transition data. The model is thus able to capture steady-state data as well as transient SI- HCCI mode transition data while maintaining a low-order cycle to cycle structure, making it tractable for model-based control of SI-HCCI mode transitions.},
}
title={A Comparison of Valving Strategies Appropriate for Multi-Mode Combustion Within a Downsized Boosted Automotive Engine: Part B—Mid Load Operation Within the SACI Combustion Regime},
author={Gerow, Matthew S and Shingne, Prasad S and Triantopoulos, Vassilis and Bohac, Stanislav V and Martz, Jason B},
booktitle={Proc. ASME 2013 Internal Combustion Engine Division Fall Technical Conference},
address={Dearborn, MI, USA},
doi={10.1115/ICEF2013-19176},
pages={V001T03A024-V001T03A024-12},
year={2013},
category={conference}
abstract={Spark Assisted Compression Ignition (SACI) is a combustion mode that may offer significant efficiency improvements compared to conventional spark-ignited combustion systems. Unfortunately, SACI is constrained to a relatively narrow range of dilution levels and top dead center temperatures. Both positive valve overlap (PVO) and negative valve overlap (NVO) strategies may be utilized to attain these conditions at low and intermediate engine loads.The current work compares 1D thermodynamic simulations of PVO valving strategies and a baseline NVO strategy in a downsized boosted automotive engine with variable valve timing capability. As future downsized boosted engines may employ multiple combustion modes, the goal of this work is the definition of valving strategies appropriate for SACI combustion at low to moderate loads and SI combustion at moderate to high loads for an engine with fixed camshaft profiles. PVO durations, valve opening timings and peak lifts are investigated at low to moderate loads and are compared to a baseline NVO configuration in order to assess valving strategies appropriate for multi-mode combustion operation. A valvetrain kinematic model is used to translate the desired valve lift profiles into camshaft profiles, while a kinematic analysis is used to calculate piston to valve clearances and to define the practical limits of the PVO strategies. The NVO and PVO strategies are also compared to throttled SI operation at part load to assess the overall efficiency benefit of operating under the thermodynamic conditions of the SACI combustion regime.While the results of this study are engine specific, there are several camshaft profiles that are appropriate for the use of PVO rebreathing type valve events. For the range of PVO valve events examined and taking into consideration piston to valve interference, the use of high exhaust and low intake lifts with early exhaust valve opening timing and long PVO durations enables high levels of internal EGR with relatively low pumping losses.}
}
title={A Comparison of Valving Strategies Appropriate for Multi-Mode Combustion Within a Downsized Boosted Automotive Engine: Part A — High Load Operation Within the SI Combustion Regime},
author={Shingne, Prasad S and Gerow, Matthew S and Triantopoulos, Vassilis and Bohac, Stanislav V and Martz, Jason B},
booktitle={Proc. ASME 2013 Internal Combustion Engine Division Fall Technical Conference},
address={Dearborn, MI, USA},
doi={10.1115/ICEF2013-19238},
pages={V001T03A030-V001T03A030-10},
year={2013},
category={conference}
abstract={As future downsized boosted engines may employ multiple combustion modes, the goal of the current work is the definition of valving strategies appropriate for moderate to high load spark ignition (SI) combustion and for spark assisted compression ignition (SACI) combustion at low to moderate loads for an engine with variable valve timing capability and fixed camshaft profiles. The dilution and unburned gas temperature requirements for SACI combustion can be markedly different from those of SI; therefore it is important to ensure that a given valving strategy is appropriate for operation within both regimes. This paper compares one dimensional (1D) thermodynamic simulations of rated engine operation with positive valve overlap (PVO) and a baseline negative valve overlap (NVO) camshaft design in a boosted automotive engine with variable valve timing capability. Several peak lifts and valve open durations are investigated to guide the down-selection of camshaft profiles for further evaluation under SACI conditions in a companion paper.While the results of this study are engine specific, rated performance predictions show that the duration of both the intake and exhaust camshafts significantly impacts the ability to achieve high load operation. While it was noted that the flow through the exhaust valve chokes for the majority of the exhaust stroke for peak exhaust lifts less than 8 mm, the engine rating could be achieved with peak intake lifts as low as 4 mm. Therefore, camshafts with peak lifts of 8/4 mm exhaust/intake were down selected to facilitate multimode combustion operation with high levels of PVO. Analysis of high load operation with the down- selected camshafts indicates that peak unburned gas temperatures remain low enough to mitigate end-gas knock, while other variables such as peak cylinder pressure, turbine inlet temperature and turbocharger speed are all predicted to be within acceptable limits.}
}
title={Application of a Supercharger in a Two-Stage Boosting System for a Gasoline HCCI Engine: A Simulation Study},
author={Shingne, Prasad and Assanis, Dennis and Babajimopoulos, Aristotelis and Mond, Alan and Yilmaz, Hakan},
booktitle={Proc. ASME 2011 Internal Combustion Engine Division Fall Technical Conference},
address={Morgantown, West Virginia, USA},
doi={10.1115/ICEF2011-60220},
pages={547-556},
year={2011},
category={conference}
abstract={Recently, a number of studies have demonstrated that boosting can extend the high load limit of HCCI. This paper compares two two-stage boosting systems for a 4-cylinder, 2.0 liter engine, within the framework of a 1D engine simulation. A series two-stage boosting system wherein both high and low pressure stages are turbochargers (TCTC) is compared with another series two-stage system, where the high pressure stage from TCTC is replaced with a small supercharger (TCSC). The engine model in these configurations is operated in steady state at high load boosted HCCI points (∼ 6.5 bar BMEP) over a range of engine speeds. The comparison has been carried out by two methods: in Method I the intake pressure to the engine has been matched for both TCTC and TCSC; and in Method II, the amount of fresh charge into the engine has been matched for both systems. A detailed energy balance shows that the performance in terms of BSFC for the TCSC system is worse for Method I. However, this changes for Method II, and the TCSC system is comparable or even better than the TCTC system. This is achieved by greatly reducing the pumping losses associated with the TCTC system, while the parasitic losses of the supercharger are minimized by having to boost to lower intake pressures due to lowered back pressures in the TCSC system.}
}
title={Turbocharger Matching for a 4-Cylinder Gasoline HCCI Engine Using a 1D Engine Simulation},
author={Prasad Shingne and Dennis N. Assanis and Aristotelis Babajimopoulos and Philip Keller and David Roth and Michael Becker},
address={Detroit, Michigan, USA},
publisher={SAE International},
booktitle={SAE Technical Paper},
doi={10.4271/2010-01-2143},
year={2010},
month={10},
category={conference}
abstract={Naturally aspirated HCCI operation is typically limited to medium load operation (∼ 5 bar net IMEP) by excessive pressure rise rate. Boosting can provide the means to extend the HCCI range to higher loads. Recently, it has been shown that HCCI can achieve loads of up to 16.3 bar of gross IMEP by boosting the intake pressure to more than 3 bar, using externally driven compressors. However, investigating HCCI performance over the entire speed-load range with real turbocharger systems still remains an open topic for research.A 1 - D simulation of a 4 - cylinder 2.0 liter engine model operated in HCCI mode was used to match it with off-the-shelf turbocharger systems. The engine and turbocharger system was simulated to identify maximum load limits over a range of engine speeds. Low exhaust enthalpy due to the low temperatures that are characteristic of HCCI combustion caused increased back-pressure and high pumping losses and demanded the use of a small and more efficient turbocharger. The paper shows that the load range of naturally aspirated HCCI can be noticeably extended to ∼12 bar net IMEP, while achieving net indicated efficiencies of ∼37 % at 2500 rpm, where the turbocharger was best matched. The study shows that there is significant potential to achieve load extension with existing turbochargers; however the load increase strongly depends on the turbocharger selection and matching.}
}
author = {Mond, Alan and Babajimopoulos, Aristotelis and Shingne, Prasad Sunand and Yilmaz, Hakan and Assanis, Dionissios},
assignee = {Robert Bosch GmbH},
address = {Stuttgart, DE},
title = {Compounded dilution and air charging device},
nationality = {U.S.},
number = {61477878},
dayfiled = {23},
monthfiled = dec,
yearfiled = {2011},
day = {},
month = {},
year = {},
type = {Patent Application},
category = {patapp},
}
title={Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection},
author={Shingne, Prasad Sunand},
year={2015},
school={University of Michigan},
address={Ann Arbor, Michigan, USA}
}