Validated 1D/3D Coupling Method to Solve Transient Flows in Internal Combustion Engines

2002 ◽  
Author(s):  
Rory Sinclair ◽  
Peter Schindler ◽  
Tim Strauss
Keyword(s):  
Gas Dynamics ◽  
Internal Combustion Engines ◽  
Numerical Procedure ◽  
3D Models ◽  
Combustion Engines ◽  
Pressure Measurements ◽  
Automotive Engine ◽  
Transient Flows ◽  
Coupled Calculation ◽  
Boundary Velocity

In this paper an improved numerical procedure [1] to calculate the gas dynamics within an automotive engine using hybrid 1D/3D models is presented. The hybrid models are solved using a coupled calculation of a 1D-finite differencing-code and a 3D-finite volume-code. The overall methodology is reviewed, emphasising new improvements to the averaging procedure. A simply method for the boundary velocity profile initialisation is discussed. Computational results from a hybrid model of a V6 TDI engine are discussed and compared to pressure measurements for three engine speeds.

Engine Control Using Cylinder Pressure: Past, Present, and Future

1993 ◽  
Vol 115 (2B) ◽  
pp. 343-350 ◽  
Author(s):  
J. David Powell
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engines ◽  
Engine Control ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Automotive Engine ◽  
Spark Timing ◽  
The Cost ◽  
Misfire Detection ◽  
Charge Temperature

Research into the use of cylinder pressure measurements from reciprocating internal combustion engines for real time automotive engine control has been investigated for the last 20 years. The measurement has been investigated for spark timing, fuel-air ratio control, charge temperature measurements, and misfire detection. The cost of the sensors has inhibited widespread use in production vehicles; however, it was introduced in domestic Japanese production for spark control five years ago. Its use for misfire detection is also being actively considered.

Maximum efficiencies for internal combustion engines: Thermodynamic limitations

2017 ◽  
Vol 19 (10) ◽  
pp. 1005-1023 ◽  
Author(s):  
Jerald A Caton
Keyword(s):  
Heat Transfer ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Pressure Rise ◽  
Internal Combustion ◽  
Thermodynamic Evaluation ◽  
Combustion Engines ◽  
Automotive Engine ◽  
Specific Heats ◽  
Cycle Simulation

The thermodynamic limitation for the maximum efficiencies of internal combustion engines is an important consideration for the design and development of future engines. Knowing these limits helps direct resources to those areas with the most potential for improvements. Using an engine cycle simulation which includes the first and second laws of thermodynamics, this study has determined the fundamental thermodynamics that are responsible for these limits. This work has considered an automotive engine and has quantified the maximum efficiencies starting with the most ideal conditions. These ideal conditions included no heat losses, no mechanical friction, lean operation, and short burn durations. Then, each of these idealizations is removed in a step-by-step fashion until a configuration that represents current engines is obtained. During this process, a systematic thermodynamic evaluation was completed to determine the fundamental reasons for the limitations of the maximum efficiencies. For the most ideal assumptions, for compression ratios of 20 and 30, the thermal efficiencies were 62.5% and 66.9%, respectively. These limits are largely a result of the combustion irreversibilities. As each of the idealizations is relaxed, the thermal efficiencies continue to decrease. High compression ratios are identified as an important aspect for high-efficiency engines. Cylinder heat transfer was found to be one of the largest impediments to high efficiency. Reducing cylinder heat transfer, however, is difficult and may not result in much direct increases of piston work due to decreases of the ratio of specific heats. Throughout this work, the importance of high values of the ratio of specific heats was identified as important for achieving high thermal efficiencies. Depending on the selection of constraints, different values may be given for the maximum thermal efficiency. These constraints include the allowed values for compression ratio, heat transfer, friction, stoichiometry, cylinder pressure, and pressure rise rate.

scholarly journals Analysis of thermodynamic parameters in spark ignition VCR engine

2019 ◽  
Vol 294 ◽  
pp. 05001
Author(s):  
Patryk Urbański ◽  
Maciej Bajerlein ◽  
Jerzy Merkisz ◽  
Andrzej Ziółkowski ◽  
Dawid Gallas
Keyword(s):  
Thermodynamic Parameters ◽  
Motion Analysis ◽  
Internal Combustion Engines ◽  
Initial Conditions ◽  
Combustion Process ◽  
Internal Combustion ◽  
3D Models ◽  
Spark Ignition ◽  
Combustion Engines ◽  
Combustion Processes

3D models of Szymkowiak and conventional engines were created in the Solidworks program. During the motion analysis, the characteristics of the piston path were analyzed for the two considered engine units. The imported file with the generated piston routes was used in the AVL Fire program, which simulated combustion processes in the two engines with identical initial conditions. The configurations for two different compression ratios were taken into account. The basic thermodynamic parameters occurring during the combustion process in internal combustion engines were analyzed.

Exhaust System Gas-Dynamics in Internal Combustion Engines

2006 ◽  
Author(s):  
R. Pearson ◽  
M. Bassett ◽  
P. Virr ◽  
S. Lever ◽  
A. Early
Keyword(s):  
Gas Dynamics ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Exhaust System ◽  
Combustion Engines ◽  
Cycle Simulation ◽  
Model Following ◽  
Analytical Tools ◽  
Empirical Approaches ◽  
Engine Cycle

The sensitivity of engine performance to gas-dynamic phenomena in the exhaust system has been known for around 100 years but is still relatively poorly understood. The nonlinearity of the wave-propagation behaviour renders simple empirical approaches ineffective, even in a single-cylinder engine. The adoption of analytical tools such as engine-cycle-simulation codes has enabled greater understanding of the tuning mechanisms but for multi-cylinder engines has required the development of accurate models for pipe junctions. The present work examines the propagation of pressure waves through pipe junctions using shock-tube rigs in order to validate a computational model. Following this the effects of exhaust-system gas dynamics on engine performance are discussed using the results from an engine-cycle-simulation program based on the equations of one-dimensional compressible fluid flow.

Intercooler model for unsteady flows in engine manifolds

1998 ◽  
Vol 212 (2) ◽  
pp. 119-132 ◽  
Author(s):  
P A Bromnick ◽  
R J Pearson ◽  
D E Winterbone
Keyword(s):  
Heat Exchanger ◽  
Gas Dynamics ◽  
Internal Combustion Engines ◽  
Unsteady Flows ◽  
Cross Flow ◽  
Combustion Engines ◽  
Medium Speed ◽  
Mass Flowrate ◽  
Flow Heat ◽  
The Relationship

A model has been developed for intercoolers which are used to reduce the temperature of the charge air in turbocharged internal combustion engines. The detailed theory for the intercooler model is presented. The behaviour of the intercooler is characterized by the relationship between the number of transfer units ( NTU) and the effectiveness (ε) of the intercooler, which is assumed to be that of a cross-flow heat exchanger. The structure of the code used to implement the model is presented and the model is applied to simulate the gas dynamics in a medium-speed turbocharged and intercooled diesel engine. The results show the predicted variation of pressure, temperature and mass flowrate across the intercooler and also the variation of intercooler effectiveness with mass flowrate.

scholarly journals A One-Dimensional Gas Dynamics Code for Turbocharger Turbine Pulsating Flow Performance Modelling

2017 ◽  
Author(s):  
Adam Feneley ◽  
Apostolos Pesiridis ◽  
Hua Chen
Keyword(s):  
Heat Transfer ◽  
Performance Prediction ◽  
Gas Dynamics ◽  
Internal Combustion Engines ◽  
Early Stage ◽  
Engine Performance ◽  
Combustion Engines ◽  
Transfer Effects ◽  
One Dimensional ◽  
Heat Transfer Effects

As governments around the world ramp up their efforts to reduce CO2 emissions, downsizing internal combustion engines has become a dominant trend in the automotive industry. Air charging systems are being utilised to increase power density and therefore lower emissions by downsizing internal combustion engines. Turbocharging represents the majority of these air charging systems, which are commonly adopted for commercial and passenger vehicles. The process of matching turbomachinery to an engine during early-stage development is important to achieving maximum engine performance in terms of power output and the reduction of emissions. Despite on-engine conditions providing highly unsteady gas flows, current turbocharger development commonly uses performance maps that are produced from steady state measurements. There are other significant sources of error to be found in early stage turbocharger performance prediction, such as the omission of heat transfer effects, and the use of data extrapolation methods to cover the entire operating range of a device from limited data sets. Realistic engine conditions provide a complex heat transfer scenario, which is dependent upon load history and the component layout of the engine bay. Heat transfer effects are particularly prevalent at low engine loads, whilst pulsating effects are significant at both high and low engine speeds (and therefore exhaust pulse frequency). Compressor maps are often provided by manufacturers with a level of heat transfer corresponding to a gas stand test, not realistic engine conditions. This causes a mismatch when using the aforementioned maps in commercial engine codes. This reduces the quality of overall engine performance predictions, since as the temperature of the exhaust gas on the turbine side rises, the performance prediction increasingly deviates from the usual adiabatic assumption used in simulations. In the present work, a one-dimensional unsteady flow model has been developed to predict the performance of a vaneless turbine under pulsating inlet conditions, with scope to account for heat transfer effects. Flow within the volute is considered to be one-dimensional and unsteady, with mass addition and withdrawal used to simulate the gas flow between the volute and rotor. Rotor passages are also treated as one-dimensional and unsteady, with the equations being solved by the method of characteristics. This model is able to simulate the circumferential feeding of the rotor from the casing, unlike many previous zero and one-dimensional models. Building upon previous work, the basis of this code has been constructed in C++ with future integration with other modern gas dynamics codes in mind. By providing the appropriate instantaneous operating conditions at specified time intervals, a code such as this could theoretically negate the need for maps produced by steady-state data.

scholarly journals THz-TDS for Detecting Glycol Contamination in Engine Oil

2020 ◽  
Vol 10 (11) ◽  
pp. 3738 ◽  
Author(s):  
Oday M. Abdulmunem ◽  
Ali Mazin Abdul-Munaim ◽  
Mario Mendez Aller ◽  
Sascha Preu ◽  
Dennis G. Watson
Keyword(s):  
Absorption Coefficient ◽  
Internal Combustion Engines ◽  
Engine Oil ◽  
Combustion Engines ◽  
Terahertz Time Domain Spectroscopy ◽  
Gasoline Engines ◽  
Automotive Engine ◽  
Four Levels ◽  
In Situ Sensor ◽  
Contamination Levels

There continues to be a need for an in-situ sensor system to monitor the engine oil of internal combustion engines. Engine oil needs to be monitored for contaminants and depletion of additives. While various sensor systems have been designed and evaluated, there is still a need to develop and evaluate new sensing technologies. This study evaluated Terahertz time-domain spectroscopy (THz-TDS) for the identification and estimation of the glycol contamination of automotive engine oil. Glycol contamination is a result of a gasket or seal leak allowing coolant to enter an engine and mix with the engine oil. An engine oil intended for use in both diesel and gasoline engines was obtained. Fresh engine oil samples were contaminated with four levels of glycol (0 ppm, 150 ppm, 300 ppm, and 500 ppm). The samples were analyzed with THz-TDS and converted to frequency domain parameters of refractive index and absorption coefficient. While both parameters showed potential, the absorption coefficient had the best potential and was able to statistically discriminate among the four contamination levels.

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