Engine Performance Parameters Research Articles

New application to reduce NOx emissions of diesel engines: Electronically controlled direct water injection at compression stroke

In this study, the effect of Direct Water Injection (DWI) on the performance, emissions and combustion was experimentally investigated on a light-duty water-cooled direct injection, diesel engine. Water was injected into the combustion chamber under full load conditions with a dedicated water injector placed on the cylinder head at 10%, 20%, 40%, 60%, 80% and 100% of the fuel by mass, namely W10, W20, W40, W60, W80, W100, respectively. The injection quantity and start of injection in degrees crank angle (°CA) for water injector were controlled by an electronic control unit. Initially, standard engine values were obtained by fueling the engine with diesel fuel for full load condition, and then experiments were repeated at different DWI ratios. Reductions in NOx emissions up to 61% were obtained after applying DWI to the engine during the compression stroke. In addition, considerable improvements were observed in engine performance parameters. It was found out that, engine power increased by 3.7% and specific fuel consumption (SFC) decreased by 4.1%. There were not significant changes in exhaust gas emissions, CO and smoke, while hydrocarbon (HC) emissions increased. Considering all parameters, the optimum condition was obtained forW60-DWI ratio. It was determined that, the water injection performed during compression stroke decreased negative compression and increased cumulative heat release.

Experimental investigation of pomegranate oil methyl ester in ceramic coated engine at different operating condition in direct injection diesel engine with energy and exergy analysis

The present work give emphasis to investigate the exergy and energy analysis of 20% pomegranate seed oil methyl ester with engine operating parameters modification at thermally coated engine. The present work intends to find the optimum engine operating parameters in ceramic coated diesel engine. The engine was initiated with diesel as a working fuel. Followed by, the conventional engine was allowed to work with pomegranate seed oil methyl ester at standard compression ratio, injection timing and injection pressure. The engine operating conditions were altered in 5.2 kW, 1500 rpm, single cylinder water-cooled direct injection engine. In order to utilize the available heat energy, the combustion chamber components were coated with Yttria Stabilized Zirconia. An attempt has been made to use biodiesel sample at varying compression ratio, injection pressure and injection timing by retarding and advancing the standard condition in both conventional engine and thermal barrier coated engine. The variables determined were energy and exergy prospective of cooling water, combustion, fuel input, performance, shaft work and emission characteristics and second law efficiency. From the results, it was observed that the biodiesel sample showed significant engine characteristics at high compression ratio, injection pressure and injection timing in thermally coated engine. In addition, the aforesaid combination offered a considerable performance in thermodynamic analysis of biodiesel sample in both conventional engine and thermal barrier coated engine. The practice of using pomegranate seed oil methyl ester (B20) with engine operating parameters modification in Yttria Stabilized Zirconia coated engine may be considered as the advantageous approach to achieve better engine characteristics.

Analysis on the operating performance of 5-kW class solid oxide fuel cell-internal combustion engine hybrid system using spark-assisted ignition

The objective of the proposed hybrid system is to increase the system efficiency by using the residual fuel of the anode off-gas from a solid oxide fuel cell in an internal combustion engine (ICE). In this study, a novel hybrid system using spark-assisted ignition (SAI) in an ICE operation is proposed. Since this is the first attempt of using a new combustion concept in a hybrid system, feasibility of SAI and its effect on the system operation are investigated in this study. To analyze the effect of the combustion on the system, the engine experiments on the SAI were conducted by changing the engine operating parameters, such as the intake temperature, equivalence ratio, and spark timing. For the system-level analysis, a zero-dimensional model for the fuel cell and the balance of plants was developed and validated. The results of the engine experiments were integrated directly with the system model. The performance of the hybrid system using SAI was analyzed from the energy and exergy perspectives. Under the operating conditions of this study, the anode off-gas combustion can be controlled stably (COV: 5–7%) through the SAI, even though the intake temperature is decreased to ~280 °C at the low compression ratio of 8.2. It leads to an increase in exergy efficiency of the engine to ~37%. Consequently, thermal self-sustainability is improved and the indicated efficiency of ~61.6% is achieved in the hybrid system. The SAI engine is responsible for ~14% of the system power and produces considerably low NOX emissions (<~3 ppm at 15% O2 on a dry basis).

Exhaust emissions generated under actual operating conditions from a hybrid vehicle and an electric one fitted with a range extender

The paper describes exhaust emission tests performed on a PHEV (Plug-in Hybrid Electric Vehicle) and a BEV (Battery Electric Vehicle), in which the combustion engine was used as a range extender. The measurements of the exhaust emissions were performed for CO2/fuel consumption, CO, THC and NOx. The RDE measurements were performed including the engine operating parameters and emissionsanalysis. This analysis shows that the engines of BEVs and PHEVs operate in a different parameter range when under actual operating conditions, which directly translates into the exhaust emission values. This is particularly the case for the emission of NOx. The investigations were carried out for two routes differentiated by the length and share of the urban and extra-urban cycles. For both routes, the emission of THC and CO were lower for the PHEV engine – HC by 69% (22 mg/km, route 1) and 6% (15 mg/km, route 2), CO by 69% (0.12 mg/km, route 1) and 80% (0.1 mg/km, route 2). For route 1, characterized by a greater share of the urban cycle, the emission of NOx was lower by 70% (2 mg/km) for the BEV engine, and (route 2) lower by 60% (8 mg/km) for the PHEV engine. Additionally, the curves of the exhaust emissions in time for individual exhaust components have been presented that indicate that in the motorway cycle the emission of THC and CO from the BEV vehicle increases significantly up to ten times compared to urban cycle.

Optimization and study of performance parameters in an engine fueled with hydrogen

Engine performance parameters, including fuel conversion efficiency (FCE), power, torque and specific fuel consumption (SFC), can be affected by variables such as ignition timing (IGT), injection timing (IT) and hydrogen volume fraction (H2%). In this paper an engine fueled with different H2/CNG blend rations from 0 to 50% volume under ignition and injection timing at different speeds were investigated. For model validation, the engine operating conditions were simulated using the AVL fire software and compared with experimental results. The statistical comparison showed that there was no significant difference between them. Also, a support vector machine (SVM) was used to study the engine's behavior according to the variables studied. The SVM model predicted the FCE, power, torque, SFC and CO with error of less than 4%. The Genetic Algorithm (GA) was used to find optimal IGT, IT and H2% values to achieve optimum engine performance. Therefore, the results showed that the optimum engine operating conditions depend on the engine speed. Also, the results showed that independent variables (IT, IGT and H2%) maximize the engine performance and minimize SFC and CO emission. So that the optimum use of hydrogen in this research at different engine speeds was between 20% and 30%.

Effect of nano-enriched emulsified Pongamia biodiesel on combustion, performance and emission parameters of a compression ignition engine

Purpose Compression ignition engines are being used in transportation, agricultural and industrial sectors due to its durability, fuel economy and higher efficiency. This paper aims to present investigation focuses on the utilization of nano additives in emulsified blends of Pongamia biodiesel and its impact on combustion, emission and performance characteristics of a diesel engine. Design/methodology/approach Pongamia biodiesel was produced through two-stage transesterification process. Taguchi method with L9 Design of experiment was adopted to study the stability of fuel blends and 75 per cent diesel, 20 per cent biodiesel, 5 per cent water and 6 per cent of surfactant was found to be stable. Further, aluminum oxide nanoparticle was blended into the emulsified fuel in mass fraction of 100 ppm (D75-BD20-W5-S6-AO100) through ultrasonicating technique. Findings Oleic acid was found to be in prominent proportion in the Pongamia biodiesel. It was observed that D75-BD20-W5-S6 and D75-BD20-W5-S6-AO100 had the ability to produce lower in-cylinder pressure and rate of heat release compared to D100, B100 and D75-BD20 fuel blends. However, a higher rate of pressure rise was noticed in D75-BD20-W5-S6 and D75-BD20-W5-S6-AO100. Lower brake specific fuel consumption and relatively higher brake thermal efficiency were noticed in D75-BD20-W5-S6 and D75-BD20-W5-S6-AO100. Moreover, lower NOx and smoke emission were also observed for nano-emulsified fuel blends. Originality/value Metal-based nano-additive significantly improved the physio-chemical properties of the fuel. Based on the literature, it is understood that emulsified biodiesel blend with nano enrichment using Pongamia biodiesel as base fuel was not carried out. Identifying a stable blend of diesel-biodiesel-water-nano additive using Taguchi’s design of experiments approach was an added value in formulating the test fuels. Furthermore, the formulated test fuel was compared with mineral diesel, biodiesel, and diesel-biodiesel blend to understand its suitability to use as a fuel in compression ignition (CI) engine.

Sustainability of the polanga biodiesel blends during the application to the diesel engine performance and emission parameters—Taguchi and RSM approach

The excessive use of fossil fuels has caused a rapid increase in air pollution all over the world. This alarming situation demands that environment-friendly fuels and their performance must be investigated for the diesel engine. The present study investigates a CI engine fueled with polanga biodiesel for the optimum performance and emission parameters. This study also tries to optimize the input parameters in order to achieve the corresponding optimized engine performance. In the present work, various input parameters such as injection timing and an injection pressure of fuel, different percentage blends of polanga-based biodiesel, and engine load are considered for optimization. The optimized output parameters are corresponding to these input parameters namely thermal efficiency, EGT, Pmax, and UHC emissions. The experiment was conducted on the diesel engine according to the CCRD matrix design. The aforesaid engine’s input parameters are found to be optimal at 22.35°bTDC fuel injection timing, 19.27 MPa injection pressure, 23.33% mixing of polanga biodiesel with diesel, at 80% engine load. Optimized and experimental results of the engine responses at optimized engine settings are compared and found within the recommended error range.

Crude palm oil as a complementary fuel for power generation in Amazonia: diesel engine performance, emissions, and economic assessment

This paper evaluates internal combustion engine performance parameters (Specific Fuel Consumption and engine torque) and pollutant emissions (O2, CO, and NOX), and also, provide an assessment of economic viability for operation in Amazonas state. Power supply to the communities in the Amazon region has as characteristics high costs for energy generation and low fare. Extractive activities include plenty of oily plant species, with potential use as biofuel for ICE (Diesel cycle) to obtain power generation together with pollutant emission reduction in comparison to fossil fuel. Experimental tests were carried out with five fuel blends (crude palm oil) and diesel, at constant angular speed (2,500 RPM – stationary regime), and four nominal engine loads (0%, 50%, 75%, and 100%) in a test bench dynamometer for an engine-driven generator for electrical-power, 4-Stroke internal combustion engine, Diesel cycle. Main conclusions are: a) SFC and torque are at the same order of magnitude for PO-00 (diesel) and PO-xx at BHP50/75/100%; b) O2 emissions show consistent decreasing behavior as BHP increases, compatible to a rich air-fuel ratio (λ &gt; 1) and, at the same BHP condition, O2 (%) is slightly lower for higher PO-xx content; c) The CO emissions for PO-00 consistently decrease while the BHP increases, as for PO-xx those values present a non-linear behavior; at BHP75%-100_loads, CO emissions are higher for PO-20 and PO-25 in comparison to PO-00; d) The overall trend for NOX emissions is to increase, the higher the BHP; In general, NOx emissions are lower for PO-xx in comparison to PO-00, except for PO-10 which presents slightly higher values than PO-00 for all BHP range; e) Assessment on-trend costs indicates that using palm oil blends for Diesel engine-driven generators in the Amazon region is economically feasible, with an appropriate recommendation for a rated power higher than 800 kW.

A Research On Dual Fuel Operation On Lhr Diesel Engine

Importance of this investigation is 100% biodiesel make use as fuel for low heat rejection (LHR) diesel engine. Due to this reason bio-fuels namely, eucalyptus oil and paradise oil were selected and used as dual fuel. Conventional engine hardware parts were coated with lanthana-doped yttria-stabilized zirconia (the doping of YSZ coatings with small amount of La2O3) with a thickness of 300 μm, so as to analyze the operating parameters of paradise oil–eucalyptus oil blends. Tests run were replicated on the conventional diesel engine and outcomes were compared. Test outcomes confirmed that the major intention of this research was attained as engine operating parameters like, brake thermal efficiency, exhaust gas temperature were increase with decrease of fuel consumption. In addition, engine emissions of HC, CO and smoke were reduced with exception of NOx for LHR diesel engine than conventional engine.

An improved multivariable generalized predictive control algorithm for direct performance control of gas turbine engine

Providing thrust for the aircrafts is the primary task of the gas turbine engine. Accurate and safe thrust controller design has always been the focus of the research. In this paper, an improved control algorithm for direct performance control of the gas turbine engine is proposed to realize the on-line estimation and tracking of the performance parameters. The controlled plant, identification module, controller and diagnosis module are integrated as a complete system, which has two loops. First, the adaptive model calculates the engine's performance parameters (thrust and compressor surge margin) as the feedback of the controller; then a Quantum-behaved Particle Swarm Optimization (QPSO) based multivariable generalized predictive controller (MGPC) is adopted as the main controller. To solve complex nonlinear optimization problems with constraints, the basic QPSO algorithm is improved from two aspects, global average best position and initial global best position. In addition, a penalty factor is added to the cost function to realize the limit protection of the rotor speed and exhaust gas temperature (EGT). Compared with the traditional control methods, the main contribution of this paper to realize the direct performance control without the conversion by the rotor speed, and the control system is responsible for limit protection and fault diagnosis in the meanwhile. Finally, simulations are performed to investigate the response of the performance parameters, the effects of the controller parameters, the ability of fault tolerance of the controller, and robustness against measurement noise and model uncertainties. The results show that the proposed scheme is robust and can achieve accurate regulation of the performance parameters and the limited outputs within the safe range, whether there is any fault or not.

Performance Analysis of Direct Injection Diesel Engine Fueled with Diesel-Tomato Seed Oil Biodiesel Blending by ANOVA and ANN

Biodiesel is an alternative fuel for diesel engine. Considering the differences between diesel and biodiesel fuels, the engine condition should be modified based on the fuel or fuel blends to achieve optimum performance. This study presented a performance analysis of a direct-injected (DI) diesel engine with a dynamometer fueled with diesel-tomato seed biodiesel (TSOB) blends employing ANOVA and universal nonlinear model based on ANN. The experiments were carried out under conditions of some independent variables including different engine loads (0, 50, 100%) and speed (1800, 2150, and 2500 rpm) for four diesel-biodiesel combinations (B0, B5, B10, and B20). In this research, the effect of these factors on dependent variables including power, torque, SFC, FC, and Exhaust Gas Temperature (EGT) are investigated. Duncan′s multi-domain test at a significance level of R &lt; 0.01 shows that the highest and lowest of the torque and power are produced from B5 and B20, respectively. These results show that the lowest EGT of 613 K is related to B20 and the highest EGT is related to B5 and B10. The regression models showed that the torque decreases with increasing the engine speed and biodiesel percentage. These results also show that the highest and the lowest SFC is related to B0 and B20, respectively. The ANN model shows high capability of predicting the engine performance parameters and emissions, without running costly and time-consuming experiments with the histogram error of 0.004 and R = 0.96. It also proved that ANN is a non-linear model of choice to deal with these data, instead of multivariate linear regression employed for preliminary analysis.

Effects of blends of castor oil with pure diesel on performance parameters of direct injection compression ignition engine

Abstract This paper deals with an experimental study of a constant speed diesel engine for various blends of castor oil and pure diesel on the performance parameters of a diesel engine. The diesel engine with constant compression ratio (i.e. 18) is used with blend of pure diesel and castor oil (10%, 20%, 30% and 40%). Results indicate that the blend C20D80 gives higher indicated power than that of diesel by 550 W. It has also been observed that IMEP of C20D80 is higher than that of diesel by 1.18 bar and 0.7 bar at no-load condition and full load condition respectively. The brake thermal efficiency of blend C40D60 is higher as compared to pure diesel by 0.15% at 50% of engine load and by 0.17% at 100% of engine load respectively. Brake specific fuel consumption has higher value for blend C20D80 at engine load of 0 to 25%. It is observed that the blend C20D80 produces best results among all blends and close to pure diesel for performance parameters of a diesel engine.

Parametric optimization of a direct injection ‐ compression ignition engine fuelled with butanol/diesel blend using response surface methodology

AbstractThis paper presents results of a simulation study on the performance and emission characteristics of a direct injection compression ignition engine, fuelled with butanol/diesel blend (20% of butanol‐by volume, called as Bu20). The aim of this study is identify optimum values of the engine operating parameters for this Bu20 fuel, which give the best performance with minimum emissions. CONVERGE CFD software was used to carry‐out the simulation studies. Simulation studies were carried out by varying four operating parameters of the engine, viz., compression ratio (CR) (16.5, 17.5, and 18.5), fuel injection pressure (FIP) (200, 220, and 240 bar), start of injection (SOI) (21, 23, and 25° CA bTDC) and exhaust gas recirculation (EGR) (0, 10, and 20%). The engine performance was evaluated in terms of indicated specific fuel consumption (ISFC), soot and oxides of nitrogen (NOx). Response surface methodology was employed for developing response models for the three output parameters considered, that is, ISFC, NOx, and soot. From the analysis of variance, it was observed that all the developed response models were statistically significant. Desirability approach was used to find the optimum combination of the input parameters with an objective of minimizing the three output responses that is, ISFC, NOx, and soot. The analysis showed that engine operation with optimum values of the operating parameters, that is, CR of 17.5, FIP of 240 bar, SOI of 25° CA bTDC and EGR rate of 10% would give better performance with minimum emissions for Bu20 fuel, compared to the engine performance with baseline configuration.

Development of simulation metamodels to predict the performance and exhaust emission parameters of a spark ignition engine

Developing more energy-efficient and environmentally friendly transportation technologies, that can enable to use significantly less petroleum and to reduce regulated emissions while meeting or exceeding drivers’ performance expectations, has always been one of the main challenges in automotive technology. Therefore, based on an experimental dataset, metamodels were generated using design of computer experiments and central composite design technique in order to accurately predict carbon monoxide (CO), oxides of nitrogen ($$\text {NO}_{x}$$), hydrocarbon (HC) and carbon dioxide ($$\text {CO}_{2}$$) emissions, mean effective pressure and exergy destruction due to heat transfer and combustion process. Combustion metamodels was evaluated varying air–fuel ratio, ignition timing [($$^{\circ }$$CAD) Crank Angle Degrees], compression ratio, and combustion duration ($$^{\circ }$$) on the performance of a Spark Ignition (SI) engine at constant speed of 750 rpm. Because SI gasoline engines always encounter the decreased thermal efficiency and increased toxic emissions at idle (Jurgen in Automotive electronics handbook, McGraw-Hill, New York, 1995). The Akaike information criterion was applied to automatically select the best metamodel for each case.

Modeling of Energy Efficiency of a Turboprop Engine using Ant Colony Optimisation

ABSTRACTExergy efficiency can be used as an objective function in order to improve systems efficiency. Thus, the most efficient regions for the operation parameters can be searched easily. Exergy efficiency data of a turboprop engine’s components that have been calculated using basic engine parameters in the previous studies are modeled using cubic spline curve fitting methodology. Spline curves are on the two dimensional plane, where x axis is the input parameter and y axis is the exergy efficiency of the component. A spline curve is defined by the points subject to arbitrary selection of number and position. Initially positions of the points are located with two different methods and then in order to obtain better accuracy point positions are improved by ‘Ant colony’ and ‘Goldsection’ optimisation methods. Sum of Squares of the errors between the fitted value and data value was used as the fitness function. Least square error of 5 × 10−9 is assumed as acceptable accuracy which yields to a minimum R = 0.9998 linear correlation coefficient. In the optimisation step, independent engine variable versus calculated engine performance parameters were checked against spline fitted values. Improvement of the fitness function is observed as the number of fitting points is increased. Ant colony optimisation in engine exergy efficiency parametric modeling is a new approach in authors’ point of view.

An assessment of diesel ethanol blend fueled diesel engine characteristics using butanol as cosolvent for optimum operating parameters

ABSTRACT Researchers found Diesel ethanol blends as one of the potential alternatives to fuel diesel engine and indicated that 45% ethanol can be utilized along with diesel using 10% butanol as co-solvent. However, the performance of this blend was found inferior compared to that of diesel. Hence, it is necessary to identify the engine operating parameters at which this blend performs better. The present study aims to utilize 45% ethanol by volume into diesel using 10% butanol as co-solvent in diesel engine and to identify the optimal engine operating parameters. The experimental study investigates the performance, combustion and emission characteristics of the Diesel Ethanol blend by varying the engine operating parameters, namely, Injection Timing, Nozzle Opening Pressure and Compression Ratio for various load conditions in a CI engine. The experiments to be conducted for determining optimal level of the three engine operating parameters were designed by Taguchi method using L9 orthogonal array. Then, the blend was tested as per the design of experiments for various engine operating parameters as fuel in a diesel engine under various load conditions. The results were compared to that of diesel as a base fuel. The test results showed that fuel blend produced 40.5% higher brake thermal efficiency and 33.5% increase in oxides of emissions when operated under Injection Pressure −190 bar, Injection Timing −29⁰ before top dead center (BTDC) and Compression Ratio – 19:1 compared to those operated under standard parameters. However, the emissions of CO & HC are found slightly higher compared to that of diesel.

Operational stability of a spark ignition engine fuelled by low H2 content synthesis gas: Thermodynamic analysis of combustion and pollutants formation

The paper focuses on the implementation of a comprehensive and robust optimization procedure for a synthesis gas fired four-cylinder, spark ignited, 2.2 L industrial engine used in combined heat and power applications. Innovatively designed workflow is for the first time incorporating also a thorough operational stability analysis for evaluation of the engine operation durability while using off-design fuels. Design constraints of the engine operational space are set after in depth investigation of knock phenomena, cycle to cycle variations, emission formation phenomena and engine performance parameters. These are derived from experimental data, obtained from the engine, equipped with newly designed components. Throughout the paper, results obtained with synthesis gas are benchmarked to natural gas. With significant emphasis laid on analysis of lean operation conditions, as a measure to reduce environmental footprint of energy generation, a newly proposed optimum operation points reveal a possibility to obtain TA-Luft and EPA emission limits already with stoichiometric mixture. This allows to achieve a remarkably low power de-rating factor of only 16.5% and omission of any aftertreatment system. Therefore, findings of this study represent a significant improvement of current control strategies and enable further increase in specific power and thus economic attractiveness of distributed power generation techniques at enhanced durability while using low-carbon and renewable fuels.

Multivariate analysis of performance and emission parameters in a diesel engine using biodiesel and oxygenated additive

Rising concerns over environmental and health issues of internal combustion engines, along with growing energy demands, have motivated investigation into alternative fuels derived from biomasses, such as biodiesel. Investigating engine and exhaust emission behaviour of such alternative fuels is vital in order to assess suitability for further utilisation. Since many parameters are relevant, an effective multivariate analysis tool is required to identify the underlying factors that affect the engine performance and exhaust emissions. This study utilises principal component analysis (PCA) to present a comprehensive correlation of various engine performance and emission parameters in a compression ignition engine using diesel, biodiesel and triacetin. The results show that structure-borne acoustic emission is strongly correlated with engine parameters. Brake specific NOx, primary particle diameter and fringe length increases by increasing the rate of pressure rise. Longer ignition delay and higher engine speeds can increase the nucleation particle emissions. Higher air-fuel equivalence ratio can increase the oxidative potential of the soot by increasing fringe distance and tortuosity. The availability of oxygen in the cylinder, from the intake air or fuel, can increase soot aggregate compactness. Fuel oxygen content reduces particle mass and particle number in the accumulation mode; however, they increase the proportion of oxygenated organic species. PCA results for particle chemical and physical characteristics show that soot particles reactivity increases with fuel oxygen content.

Investigations on performance and emission parameters of direct injection diesel engine running with Mesua ferrea oil methyl ester blends

The present study deals with the experimental analysis on performance and emission characteristics of VCR diesel engine operating through Mesua ferrea oil methyl ester (MFOME) blends at different injection operating pressures of 180 bar, 200 bar, and 220 bar. Four test fuels were used in this analysis namely diesel, MFOME10, MFOME20, and MFOME30. The conventional diesel has shown higher BTE than the leftover MFOME blends while the BSFC was also lowered for conventional diesel. Emission parameters namely CO, UHC, and smoke opacity were reduced while the CO2 and NOx were greater intended for MFOME blends than conventional diesel. The similar trend was followed at all three injection pressures and better results were noticed at an injection operating pressure of 220 bar. The performance of MFOME20 is somewhat nearer to conventional diesel and better emission concerning CO, UHC, and smoke opacity were with MFOME20.

Internal Combustion Engine Heat Transfer and Wall Temperature Modeling: An Overview

Internal combustion engines are now extremely optimized, in such ways improving their performance is a costly task. Traditional engine improvement by experimental means is aided by engine thermodynamic models, reducing experimental and total project costs. For those models, accuracy is mandatory in order to offer good prediction of engine performance. Modelling of the heat transfer and wall temperature is an important task concerning the accuracy and the predictions of any engine thermodynamic model, although it is many times an overcome task. In order to perform good prediction of engine heat transfer and wall temperature, models are required for accomplish heat transfer from hot gases to engine parts, heat transfer inside each engine part, and also heat transfer to coolant and lubricating oil. This paper presents an overview about engine heat transfer and wall temperature modelling, with main purpose to aid engine thermodynamic modelling and offer more accurate predictions of engine performance, consumption and emission parameters. The most important correlation are reviewed for three engine heat transfer approaches: gas to wall, wall to wall and wall to liquid heat transfer models. In order to obtain good prediction of wall temperature, those three approaches must be coupled, which may imply convection-conduction-convection problems, although for some applications in diesel engines, radiation problems must be considered.