Internal Combustion Engine Cylinder Research Articles

Study of the conrod deformation during piston interaction with liquid in the internal combustion engine cylinder

The paper analyzes the deformation of the connecting rod stem with buckling due to water ingress into the internal combustion engine cylinder (the so-called hydrolock). A method is presented that has been developed to perform calculations of stem deformation in the process of compressing air with liquid in an internal combustion engine cylinder. The method is based on solving a system of differential equations for pressure and temperature in the cylinder, followed by calculating the compression force acting on the connecting rod. A carried-out simulation of the compression process demonstrates the dependence of the air pressure in the cylinder, the stress and the strain of the connecting rod on the fill ratio of the combustion chamber with liquid. The calculations performed according to the classical theory of resistance of materials have shown that the connecting rod with the buckling of the stem begins to deform when the liquid fills the combustion chamber to a minimum of 80%. With the increase in the amount of liquid, the deformation of the conrod increases, and when the level of liquid filling is so significant that it exceeds the volume of the combustion chamber, the conrod stem deformation reaches extreme values. It is shown that under these conditions after the hydrolock occurs the engine may fail due to the piston wedging the crankshaft in the bottom dead center position.

Simulation of the connecting rod damage when fluid enters the engine cylinder

Problem. The patterns of a conrod stem deformation during compression of air with a liquid in the internal combustion engine cylinder are considered, and the stem deformation when liquid enters the cylinder (hydrolock) is calculated. It is noted that despite the well-known nature of this damage, no quantitative data are available, which often makes it difficult to determine the damage causes in the practice of ICE operation. Goal of the work is to study the connecting rod deformation mechanism during the loss of stem stability due to hydrolock in the cylinder to obtain quantitative characteristics of this phenomenon, suitable for use in practice to determine the failure causes. Methodology includes simulation of the compression process with a liquid, as well as simulation of the deformation and the buckling of the conrod stem under axial compression. A numerical integration of a system of differential equations describing the change in pressure and air temperature with a liquid in a cylinder by the crankshaft rotation angle is carried out with the initial conditions that were obtained using the standard ICE cycle calculation program. Then the dependence of maximum pressure in the cylinder and the conrod buckling from the combustion chamber filling ratio was determined. Results. For the found strains, the axial deformation of the conrod stem was simulated using the finite element method, the buckling shape of the stem and the stress were determined, and the dependence of the longitudinal bending on the axial deformation of the stem was determined. The simulation results were compared with experimental data on the conrods damages in the ICE operation, as well as with the results of stress calculations using classical methods. Originality. For the first time, a quantitative link was determined between the liquid amount that fell into the internal combustion engine cylinder during hydrolock, the shape of the conrod stem, its axial deformation, and longitudinal bending in case of loss of stability. Practical value. The results can be used in practice when searching for the causes of the internal combustion engines faults, including simulation the ICE damages, in order to clarify the symptoms and causes of the faults associated with hydrolock. Based on the results of the study, the feasibility of the practical application of the damage simulation in studying the fault causes is substantiated. Keywords: internal combustion engine, connecting rod, hydrolock, buckling, simulation.

Development of cycle-to-cycle variation of the tumble flow motion in a cylinder of a spark ignition internal combustion engine with Miller cycle

Reducing the cycle-to-cycle variation in an engine is a key to expanding the operational limits of high-efficiency engines such as lean-burn engines. The cycle-to-cycle variation of the engine output is caused by unstable combustion and is especially induced by the cycle-to-cycle variation of the in-cylinder flow. This investigation aims to clarify how the cycle-to-cycle variation of in-cylinder flow develops during intake and compression strokes. To achieve this aim, 12 kHz time-resolved particle image velocimetry measurements were conducted on the symmetrical vertical plane in a four-valve, four-stroke optically accessible engine. This study focuses on the relationship between the flow at the plug position at the ignition timing and the flow distribution in the intake and compression stroke. Correlation map analysis reveals this relationship, and some flow distributions are extracted. The fluctuations in the flow distribution induce the cycle-to-cycle variation of the flow direction at the plug position at the ignition timing, the position of the stagnation plane between the intake flow from the intake valves and the upper side of the tumble vortex, the strength of the blowback flow into the intake port generated by the Miller cycle, and the position of the tumble vortex in the late compression stroke. The flow distributions extracted by the correlation map analysis clearly change between cycles. These results also suggest that correlation map analysis is an effective way to elucidate the factors that induce the cycle-to-cycle variation of the in-cylinder flow.

РОЗРАХУНКОВА МОДЕЛЬ ПРОЦЕСУ СТИСНЕННЯ ПОВІТРЯ З РІДИНОЮ В ЦИЛІНДРІ ДВЗ

The paper discusses the features and performs a preliminary analysis of the symptoms and the causes of the connecting rod damage of an internal combustion engine caused by liquid entering the cylinder (hy­drolock). Object of the study is the cylinder of an internal combustion engine when liquid enters it. Purpose of the study is to research the mechanism of compression air with a liquid in the engine cyl­inder for identifying currently absent quantitative characteristics of the phenomenon of hydrolock, which causes deformation (buckling) and subsequent destruction of the connecting rod. Method of the study is theoretical, includes the development of a methodology for calculating the variation of the air parameters during compression air with a liquid. Based on simplifying assumptions, a system of differential equations for the pressure and temperature of the air with a liquid in a cylinder is ob­tained from the equations of gas state and energy. The system is solved by numerical integration over the crankshaft rotation angle with initial conditions were obtained using the standard ICE cycle calculation soft­ware. As a result, computation of the cylinder pressure in compression process by the crankshaft rotation angle depending on the filling ration of the combustion chamber with liquid was performed. The practical use of the methodology and the results obtained consists in their application in the problems of the engine damage simulation, including the calculations of the connecting rod buckling during hydrolock, as well as to clarify the symptoms and the causes of the damage. By calculation using the developed methodology, it was found that with an increase in the amount of a liquid, the maximum pressure in the internal combustion engine cylinder rapidly increases during compres­sion, starting with the combustion chamber filling ratio of 80%. With a further increase in liquid filling, commensurate with the volume of the combustion chamber, pressure rise in the final phase of the compres­sion stroke is possible tens or even hundreds of times, which determines the damage to the connecting rod during hydrolock. KEYWORDS: INTERNAL COMBUSTION ENGINE, ICE, CONNECTING ROD, CYLINDER, FAILURE, DAMAGE, HYDROLOCK, SIMULATION.

Progress on the studies about NOx emission in PFI-H2ICE

Owing to its brilliant combustion performance and cleanest combustion products, hydrogen has been widely considered as one best alternative fuel for internal combustion engines. However, in the cylinder of hydrogen internal combustion engines, high combustion temperature and oxygen enrichment make NOx is still one but the only combustion pollutant. Therefore, it is particularly important to control NOx emission for hydrogen fuelled engines. Since PFI-H2ICE (port-fuel-injection hydrogen internal combustion engine) is the normal type of hydrogen fuelled engines, the present article will focus on the studies about NOx emission in PFI-H2ICE researches. First, the present article reviews the mechanism of NOx generation in PFI-H2ICE; upon chemical kinetics, the generation of NOx will be summarized and discussed into three major paths which including thermal NO path, NNH–NO path and N2O–NO path. Then, the researches on the control methods of NOx for PFI-H2ICE in recent years will be systematically reviewed, the influencing factors to reduce NOx emission will be summarized in some aspects which including combustion component control strategy, injection control strategy, ignition control strategy and engine compression ratio control strategy. To the PFI-H2ICE operated at lean fuel conditions (like equivalence ratio is less than 0.5) or rich fuel conditions (like equivalence ratio is higher than 1), the technologies and the strategies of EGR (exhaust gas re-circulation) will be reviewed and discussed. It is hoped this literature review would enable researchers to systematically understand the progress of NOx emissions research in PFI-H2ICE and explore further research directions.

Investigation on laser surface texturing for friction reduction in multi cylinder internal combustion engine

ABSTRACT The frictional losses can be reduced by proper selection of lubricating oil, the material of mating components and surface microstructure of material used in internal combustion engine. The present work focuses on the friction power reduction by changing the surface microstructure of piston rings by Laser Surface Texturing (LST). Piston ring with dimple textured is fabricated and used in the motor-driven engine to study the frictional characteristics and compared with untextured piston ring. The two series of experiments were carried out on developed multi cylinder I.C.Engine test rig under different speeds with repeatability. It is observed that there is a 26% reduction in the frictional losses with the use of texture on the piston ring. It ensures the smooth running of the engine with better performance and higher thermal efficiency. Brake power is increased by reducing friction power with the help of LST on piston ring in I.C. engine which indirectly increase thermal efficiency of I.C.Engine.

The spread of smaller engines and markets in machinery services in rural areas of South Asia

This paper is concerned with the historical spread of small scale engines in Asian countries over the last 50 years. Small, mostly single cylinder internal combustion engines (up to 24 hp) that have been used to power pumpsets, boats, vehicles, threshers, ploughs, rotators and other tillage implements, hullers, etc. The paper argues that the spread of smaller scale tractors (power tillers), pumpsets etc. is a neglected topic in the literatures, in spite of the evidence that this equipment has often contributed a significant, if not the major, source of mechanical energy for agricultural production increases and rural economic development. The paper uses two analytical frameworks to position the analysis: firstly, conventional Leontief input output economics, which looks at the interrelationships between sectors in an economy where pumps, tractors, etc. are seen as rural capital goods, and secondly, the historical literature on Appropriate Technology. It is argued in this paper that in the last few years there has been a substantial resurgence in policy interest in appropriate technology, after many years of neglect. Brief illustrative examples are given of the spread of small scale equipment, (diesel engine irrigation pumpsets, two-wheel tractors, power tillers, mini tillers and shallow tube wells). The paper discusses: the diverse histories and patterns of rural mechanization between and within countries; markets in powered services from small engines; the importance of informal R&D in rural mechanization, as well as the past prevalence, recent interest in and problematic nature of South-South technology exchanges. The paper does not set out to enter into academic debates, but does refer to some of the data and analytical problems that characterize such analysis. It concludes by suggesting that the culture of local policy discourse between researchers and policy makers is a major determinant in understanding past changes, and hence is important for future policy purposes.

A phenomenological base semi-physical thermodynamic model for the cylinder and exhaust manifold of a natural gas 2-megawatt four-stroke internal combustion engine

This paper presents the application of a systematic methodology to obtain a semi-physical model of phenomenological base for a 2 MW internal combustion engine to generate electric power operating with natural gas, as a function of the average thermodynamic value normally measured in industrial applications. Specifically, the application of the methodology is focused on the cylinders, exhaust manifold, and turbocharger turbine sections. The proposed model was validated with actual operating data, obtaining an error rate not exceeding 5%, which allow a thermal characterization of the Jenbacher JMS 612 GS-N based on the model. A parametric analysis is conducted; considering the volumetric efficiency, the output electric power, the effective efficiency, the exhaust gas temperature, the turbine mass flow, the specific fuel consumption under the nominal operation conditions, which is 1.16 bar in the gas pressure, 65 °C in the cooling water temperature, 35 °C in the average ambient temperature, and 1500 rpm. The results of this model can be used to evaluate the thermodynamic performance parameters of waste heat recovery systems. On the other hand, new control strategies and the implementation of state observers for the detection and diagnosis of failures can be developed based on the proposed model.

Prospects of Using Hydrogen Microaddition to Improve Diesel Engine Ecological Indicators

The problem of environmental degradation in megapolises, particularly because of the toxicity of the exhaust gases of transport engines, requires an integrated solution. The peculiarity of the processes of mixture formation and combustion in diesel engines is the presence of local areas, rich in fuel or air. This results in in-complete diesel fuel combustion and contributes to the formation of toxic and mutagenic-carcinogenic compounds. Exhaust gases from diesel engines contain solid particles (SPs) that, due to their developed surface, are carriers of mutagenic-carcinogenic compounds. A very important factor affecting the com-pleteness of fuel combustion in the cylinder of an internal combustion engine (ICE) is the intensive heat exchange between the walls of the combustion chamber and the working fluid. As a result, a relatively cold gas wall layer occurs. In this layer, the unburned hydrocarbons CnHm reside, and SPs are formed. The mi-croaddition of hydrogen to the incoming charge makes it possible to significantly reduce the thickness of the “cold” layer due to the intensification of the combus-tion process in the ICE cylinder and near-wall areas. The generation and use of hydrogen, on board a vehicle, as a microaddition to normal engine fuel is justified as follows. First, the activation of combustion processes in the engine cylinder and, accordingly, fuel combustion completeness increase, which helps reduce the level of mass emissions of SPs and unburned hydrocarbons with the exhaust gases from ICEs. Secondly, such an approach makes it possible to reduce the level of load on the regular exhaust gas neutralization systems of modern vehicle engines, and increase the reliability of their work and their resource. The design of the on-board small-size electrolyzer and its control algorithm are developed. Compre-hensive motor studies of the influence of hydrogen microadditions to diesel fuel on the effective 1H 8.5 / 11 diesel engine performance and the toxicity of its exhaust gases were carried out. Experimental studies show that with hydrogen microaddi-tions, owing to an increase in fuel reactivity and combustion completeness, carbon monoxide emissions and smoking at the exhaust are reduced by 5–6% and 20%, respectively, with practically no unburned hydrocarbons present. The use of the proposed design and algorithm of the on-board electrolyzer operation will signifi-cantly reduce the level of toxicity of the exhaust gases from vehicle ICEs with minimal energy consumption for the functioning of the system.

The vibration reduction design of single-cylinder engine based on the balance shaft

A 3d model of crank connecting rod of a single cylinder internal combustion engine (ICE) is established, whose force analysis was carried out in ADAMS/VIEW using virtual prototyping method. It was found that the results between the analysis and the theoretical calculation results were basically consistent, indicating that the established model is correct and reliable. In order to reduce the inertia force and torque of this ICE, the uniaxial balance method was used to carry out the vibration reduction design based on the balance shaft. The results of virtual experiments showed that the single cylinder internal combustion engine with a balance shaft can greatly reduce the inertia excitation force as well as improve the vibration.

Effects of Outlier Flow Field on the Characteristics of In-Cylinder Coherent Structures Identified by Proper Orthogonal Decomposition-Based Conditional Averaging and Quadruple Proper Orthogonal Decomposition

Proper orthogonal decomposition (POD) offers an approach to quantify cycle-to-cycle variation (CCV) of the flow field inside the internal combustion engine cylinder. POD decomposes instantaneous flow fields (also called snapshots) into a series of orthonormal flow patterns (called POD modes) and the corresponding mode coefficients. The POD modes are rank-ordered by decreasing kinetic energy content, and the low-order, high-energy modes are interpreted as constituting the large-scale coherent flow structure that varies from engine cycle to engine cycle. Various POD-based analysis techniques have thus been proposed to characterize engine flow field CCV using these low-order modes. The validity of such POD-based analyses rests, as a matter of course, on the reliability of the underlying POD results (modes and coefficients). Yet a POD mode can be disproportionately skewed by a single outlier snapshot within a large data set, and an algorithm exists to define and identify such outliers. In this paper, the effects of a candidate outlier snapshot on the results of POD-based conditional averaging and quadruple POD analyses are examined for two sets of crank angle-resolved flow fields on the midtumble plane of an optical engine cylinder recorded by high-speed particle image velocimetry (PIV). The results with and without the candidate outlier are compared and contrasted. In the case of POD-based conditional averaging, the presence of the outlier scrambles the composition of snapshot subsets that define large-scale flow pattern variations, and thus substantially alters the coherent flow structures that are identified; for quadruple POD, the shape of coherent structures and the number of modes to define them are not significantly affected by the outlier.

Development of actions on optimization of chemical composition of carburized steel grade 16MnCrS5 to eliminate the causes of the growth of large austenite grains

The problem of friction, wear of machine parts and cutting tools, the need to increase the life of machines makes the task of creating new high-performance, energy-saving technologies of hardening one of the main in engineering. In mechanical engineering, the problem of improving the physical, mechanical and operational properties in thin surface layers (~10 microns) of such parts as shafts, gears, measuring tools, drills, cylinders of internal combustion engines, etc. is important. Currently, these tasks are often solved by applying reinforcing coatings. Cementation is economical. The technology of cemented steels smelting, which is currently used by metallurgical plants, does not ensure stable production of fine-grained structure in products. At the same time, the capacity of machines and units are growing, and to obtain parts that can withstand higher loads while maintaining their overall dimensions, new steel grades are needed. The complexity of the configuration of gears with a thin tooth and a massive sleeve, and the need for minimal warping make heat treatment as difficult and responsible as a complex tool, such as shaped cutters. Therefore, for the manufacture of gears you want to assign steel with small hereditary grain size. In this article we will focus on the development and production of cemented steel in the conditions of OJSC «BSW – Management Company of Holding «BMC», in particular, the steel brand 16MnCrS5 commissioned by the European manufacturer of gearboxes and motors. To determine the grain size of the metal must be subjected to special types of processing for the manifestation of certain characteristics. These results allow us to draw conclusions about the need to adjust the chemical composition of steel grade 16MnCrS5 by introducing a system of modifying elements, which will reduce the tendency of steel to overheating, therefore, reduce the size of austenitic grains. On the basis of the revealed regularities on the influence of carbide-forming elements, a further system of steel modification is determined, which includes a complex of elements V, Nb, Ti.

Electrolytic polishing of compacted graphite iron for revealing subsurface graphite of honed cylinders

The superficial characteristics of honed surfaces are relevant for the tribological performance of cylinders of internal combustion engines (MCI). Recent studies found a correlation between the occurrence of the phenomenon called folded metal and the presence of graphite of cast irons. However, the honing process tends to overlap the graphite, such that an application of a technique to remove a thin layer of material, exposing the graphite, would be useful. This paper aims to determine the best condition, of electric potential and time, for the exposition of graphite in honed surfaces using a technique of electrolyte polishing. The polishing was made on the concave surface with aid of a polishing mask developed for this matter. Samples of honed cylinders were removed from MCI manufactured using a compacted graphite iron. The characterizations were done through metallography and white light interferometry. To determine the ideal condition, several conditions of polishing were tested. For the verification of the repeatability, five repetitions were performed with the best condition. The results showed satisfactory repeatability, with an exposition of graphite and the matrix etching. The roughness of the polished region presented considerable uniformity, with a significant change of roughness in comparison to the honed surface. Furthermore, removal of the characteristic topography of the honed surface was observed. The layer removed showed little variation in depth along the polished region, with values close to 5 µm. This value accomplishes the demand of layer removal for the exposition of subsurface graphite.

Novel, shape optimised, TEG subsystem design

This research report presents a new, innovative design and manufacturing solution to recover thermal waste heat energy, from the combustion process of the engine, without affecting the process. Our research focuses on the exhaust port of the engine cylinder, were the waste heat energy and engine coolant are available to operate the thermoelectric generator (TEG) units. A new, one-piece TEG unit, is designed and computational fluid dynamics (CFD) analyzed, to evaluate and validate effective thermal waste heat transfer into the unit subsystem, at the temperatures ranging over 800°C. Additional simulations, on the internal combustion engine (ICE) cylinder head provided data of the flow temperature distribution when directly coming from the heat source. Using TEG units’ test data, from our experiments, and data generated from our Matlab-Simulink model, we were able to validate and predict performances of the new TEG subsystem design. Our solution ensures the best surfaces matching, between the oval shaped TEG subsystem and the engine hot surface. Following that, it offers optimal energy recovery.

Determination of the pressure in the cylinder of the automotive internal combustion engine by the installation of tensommetric sensors

The analysis of well-known methods of displaying and their cost has made it possible to conclude that the methods of direct and indirect displaying have a number of serious shortcomings. Therefore, the diagnostic method for the condition of the internal combustion engine according to the value of gas pressure in the cylinders of the engine has been proposed. This method allows determining its indicator ratios, assessing the engine`s health of the ICE, the regulator (control) performance, efficiency and environmental cleanliness. This article describes the general principle of operation of the device and components of the process of measurement and processing of the obtained data. The authors of the article provided the connection diagram and substantiated the efficiency of the proposed method for obtaining information on internal cylinder processes. The results of the performed calculations indicate the suitability of the proposed calculation method for the simulation of internal cylinder processes inside internal combustion engines, including the modern ones

Experimental and numerical analysis of the in-cylinder swirl flow dependence on the pressure

The steady flow test rig is a device for studying the influence of the intake and exhaust ports of the cylinder head on the flow motion inside the cylinder in internal combustion engines. In this paper, the swirl flow as a critical mixing mechanism inside the cylinders of internal combustion engines has been investigated by the vane type swirl meter measurement system in the steady state flow test rig with experimental and numerical simulation methods. In numerical simulations, the in-cylinder flow in the presence of the swirl meter is modeled using the multiple reference frame (MRF) method. Three dimensional numerical simulations are applied by using the finite volume method. The simulation results show good agreement with experimental results and showed to be a good alternative to compensate the limitations of the operating conditions of the test rig. In this work, a linear correlation between the rotational speed of the swirl meter and the torque is found. The study also showed that by increasing the pressure difference between the inlet and outlet of the cylinder, the speed of the in-cylinder swirl flow increased where a correlation between swirl flow velocity and pressure difference is proposed using an exponential function. The in-cylinder swirl flow velocity was determined for different test pressure and for different distance the vane-type swirl meter from cylinder head and it was seen that it is maximum when the vane-type swirl meter is located at 1.3 D from cylinder head for different test pressure.

Energy Balance and Power Loss Pathway Study of a 120 cc Four-Stroke Internal Combustion Engine

Efforts to improve the range and endurance of group 2 (10–25 kg), internal combustion engine (ICE) powered unmanned aerial vehicles (UAVs) have been underway for several years at Air Force Research Laboratory (AFRL). To obtain the desired performance improvements, research into improving the overall efficiency of the ICE powerplants is of great interest. The high specific energy of hydrocarbon fuels (13,000 W h/kg for gasoline), but low fuel conversion efficiency for small ICEs means that relatively minor improvements in the fuel conversion efficiency of the engines can yield large improvements in range and endurance. Little information is available however for the efficiency of ICEs in the size range of interest (10–200 cm3 displacement volume) for group 2 UAVs. Most of the currently available efficiency data for 10–200 cm3 ICEs is for two-stroke engines. The goal of this study was to provide an in-depth probe of the efficiency and energy losses of a small displacement four-stroke engine which could potentially be used to power a group 2 UAV. Energy balances were performed on a Honda GX120 four-stroke engine using empirical research methods. The engine was a 118 cm3 displacement, single cylinder ICE. Energy pathways were characterized as a percentage of the total chemical energy available in the fuel. Energy pathways were characterized into four categories: brake power, cooling load, exhaust sensible enthalpy and incomplete combustion. The effect of five operating parameters was examined in the study. Fuel conversion efficiency ranged from 22.2% to 25.8% as engine speed was swept from 2000 to 3600 RPM, from 20.8% to 27.3% as equivalence ratio was swept from 0.85 to 1.25, and from 15.7% to 24.9% as throttle was swept from 28.5% to 100%. Combustion phasing and cylinder head temperature sweeps showed only minor changes in fuel conversion efficiency.

A Comparative Analysis of In-Cylinder Flow, Heat Transfer and Turbulence Characteristics in Different Type Combustion Chamber

Recently some studies have been carried out on combustion chamber design for diesel and gasoline engines; however, they routinely used piston bowl model approach, which may neglect interactions with cylinder head design. Fluid motion within the cylinder of internal combustion engines has a significantly influence on the combustion process and engine efficiency. The aim of this study two different geometries of the combustion chamber of internal combustion engine were compared in terms of in cylinder flow and heat transfer during the intake process. For this, complete calculations of the intake stroke were performed under realistic operating conditions and heat transfer, velocity and turbulence flow fields obtained in each combustion chamber investigation detail. They were solved with finite volume method and ANSYS-Fluent 12.0 commercial code. The findings include using k-e turbulence model and dynamic mesh generation model for different crank angle. The result of studies show that flow structure and turbulence intensity are affected on combustion chamber geometries. Also, the pent-roof type combustion chamber configuration was found to generate turbulence intensity more efficiently than the conventional type combustion chamber.

Effect of plasma spraying modes on material properties of internal combustion engine cylinder liners

The paper analyses different methods of remanufacturing worn-out machine parts in order to get the best performance characteristics. One of the most promising of them is a plasma spraying method. The mathematical models presented in the paper are intended to anticipate the results of plasma spraying, its effect on the properties of the material of internal combustion engine cylinder liners under repair. The experimental data and research results have been computer processed with Statistica 10.0 software package. The pare correlation coefficient values (R) and F-statistic criterion are given to confirm the statistical properties and adequacy of obtained regression equations.

Recursive Engine In-Cylinder Pressure Estimation Using Kalman Filter and Structural Vibration Signal

The cylinder pressure signal is a very useful indicator for modern high-performance internal-combustion (IC) engines. Unfortunately, direct measurements of the cylinder pressure are impractical because installing cylinder transducers is difficult and conditions in IC engine cylinders are adverse. Therefore, different methods have been investigated to reconstruct the cylinder pressure from externally measured signals, such as the engine structure vibration and the crank angular speed. In this paper, some of existing methods are reviewed firstly. Then a novel recursive cylinder pressure estimation method based on using the Kalman filter with the engine structure vibration signal as input is proposed. Two combustion metrics, pressure peak (Pmax) and peak location (Ploc), were used for evaluating the proposed method. The estimation results were compared with the experimental data collected from a four-cylinder diesel engine and showed the effectiveness of the proposed method.