Piston Temperature Research Articles

Geometric Stability Measurements’ of Vehicles’ Pistons in Self-Cooling Process for Define Its Wear / Współrzędnościowe Pomiary Stabilności Geometrycznej Tłoków W Procesie Stygnięcia Dla Określenia Stopnia Ich Zużycia

Abstract The paper presents the investigation method allows for an analysis of failure of combustion engines piston surface. The essence of method is realization of precise measurement in various piston temperature and after that comparison of obtained results to reference piston - new one. Method has been presented on the basis of two pistons measurements.

Finite Element Analysis of the Cylinder Liner of a 280 Diesel Engine

The Cylinder liner is one of the key components of diesel engine. Combustion chamber set is constituted by Piston, Cylinder head, Cylinder liner and other parts. Its structure and working environment is complex. Received the gas pressure, friction force from high-speed reciprocating motion of the piston and lateral force of the piston, it results in mechanical stress and mechanical deformation. High temperature combustion and high pressure gas make the piston temperature distribution uneven, which results in piston thermal stress and thermal deformation. Therefore, the element analysis of Cylinder liner in the heat load and mechanical load is significant, the finite element analysis shows the deformation and the stress distribution of the Cylinder liner. It is meaningful for improving Cylinder liner design and reliability.

Finite Element Analysis for the Temperature and Stress Fields of the Diesel Piston Based on CAE

Adopting the finite element software ANSYS, this paper calculates the temperature and stress fields of the combined piston under the conditions of cooling and no cooling. The analytical results show that the piston under no cooling condition has higher thermal load and integrative stress than the condition of cooling, because the piston head can’t get better cooling. Moreover, the high thermal load causes the piston head creating great deformation, which has exceeded the normal gap between the piston and the liner, so the piston abrasion may worsen.

The Effect of Piston Cooling Jets on Diesel Engine Piston Temperatures, Emissions and Fuel Consumption

The Effect of Piston Cooling Jets on Diesel Engine Piston Temperatures, Emissions and Fuel Consumption

Optical Piston Temperature Measurement in an Internal Combustion Engine

Optical Piston Temperature Measurement in an Internal Combustion Engine

A Short History of Large Gas Engines

In the nineteenth century large volumes of low-energy gas were wasted from blast furnaces, despite improvements such as Neilson's hot blast process, and this prompted B. H. Thwaite, in 1894, to experiment with it as a source of fuel for gas engines. His experiments were successful and gas engines, despite the low energy content of blast furnace gas, produced almost the same power as with coal gas. However, the available engines were too small to make use of the huge quantities being wasted and consequently new and much larger engines were developed very quickly, particularly in Belgium and Germany. Bore diameter increased from about 10 inches to over 60 inches in about twenty years and water-cooled, double-acting, tandem horizontal engines were adopted. Britain and the United States were content, initially, to manufacture such large engines under licence. Still larger engines would have been made except that high piston temperatures and high thermal stresses caused failures and placed an upper limit on the bore diameter and the power per unit area of piston. British manufactures solved the problem by using large numbers of smaller cylinders, arranged vertically in tandem. Modern gas engines use up to twenty-four smaller cylinders, usually arranged in vee rather than tandem formation.

Parameters of an erosion carbon plasma in the channel of a railgun

The working current dependences of the thermodynamic and electrophysical parameters of a free plasma piston moving with a near-maximal velocity in the channel of an electromagnetic rail launcher with graphite electrodes are obtained. The composition and weight of the plasma depend on the degree of electrode erosion due to discharge current passage (i = 40–80 kA). It is shown that the mean temperature of the plasma piston only slightly depends on the plasma mean pressure and plasma piston weight and increases with current by a near-power law. The measured values of the maximal velocity of the plasma piston front are compared with the calculated value of the sound velocity inside the piston. With the working current and cross-sectional area of the channel fixed, the initial gas density in the channel is found to influence the ratio of the piston maximal velocity to the sound velocity in the plasma. If the initial gas density is low (lower than some critical value), the maximal velocity of the plasma piston front exceeds the sound velocity in the plasma.

The Effects of the Cooling Gallery Position on the Piston Temperature Field and Thermal Stress

The effects of cooling gallery position on the piston temperature field and thermal stress are studied. A finite element model of 1015 engine piston is developed using Pro/E software and finite element analyses are achieved through ANSYS code. Numerical simulations are performed to find the temperature and thermal stress change rules with regard to the cooling gallery position. The results demonstrate that the axial direction position of cooling gallery has obvious effects on the piston temperature while the radial direction position of cooling gallery affects the piston thermal stress a lot. The highest position of cooling gallery should be as the same line as the top of the first ring groove. The distance between cooling gallery and piston radial edge should be more than a certain value to decrease the temperature gradient and thermal stress concentration.

Thermal analysis of a partially ceramic coated piston: Effect on cold start HC emission in a spark ignition engine

Abstract Effect of partially thermal barrier coating on piston temperature distribution and cold start HC emissions of a spark ignition (SI) engine are investigated numerically and experimentally. A Thermal analysis was performed for both standard and coated pistons by using a commercial code, namely ANSYS. The engine tests were conducted on a single cylinder, water cooled SI engine for both standard and coated cases. Analysis results show that the surface temperature of the coated piston part was increased up to 100 °C, which leads to an increase in air–fuel mixture temperature in the crevice and wall quenching regions. Thus, cold start HC emissions considerably decrease compared to the standard engine without any degradation in engine performance. Maximum decrease in HC emissions was 43.2% compared to the standard engine.

A contribution to film coefficient estimation in piston cooling galleries

The need to reduce fuel consumption and exhaust emissions in internal combustion engines has been drastically increased during last years. One of the most important processes affecting these parameters is heat transfer from the in-cylinder gas to the surrounding walls, as this mechanism has a direct influence on the combustion process. Regarding the different walls (liner, cylinder head and piston surfaces), heat flow to the piston is especially important, as it is essential to avoid excessively high temperatures that could result in material damage and/or oil cracking. With this purpose different cooling strategies are used, among which the improvement of the piston cooling system by using oil galleries is preferred. In this work, the heat flow through the oil gallery in a Diesel piston was investigated on a dedicated test bench. This bench consists of a controlled heat source and a piston oil cooling system in which different test conditions were evaluated in order to obtain a correlation for the film coefficient associated with piston oil cooling. These experimental results were then incorporated into a lumped model for engine heat transfer. Finally, in order to evaluate the accuracy of this model and the effects of the correlation for oil gallery coefficient on engine heat flows, results obtained on a conventional engine test bench equipped with a Diesel engine, in which two piston temperatures had been measured, were used. The results show an improvement in piston temperature predictions when compared with those obtained using a previously reported expression for the calculation of the oil film coefficient.

Piston Pin Dynamics and Temperature in a C.I. Engine

Piston Pin Dynamics and Temperature in a C.I. Engine

Transient Analysis of the Piston Temperature with Consideration of In-cylinder Phenomena Using Engine Measurement and Heat Transfer Simulation Coupled with Three-dimensional Combustion Simulation

Transient Analysis of the Piston Temperature with Consideration of In-cylinder Phenomena Using Engine Measurement and Heat Transfer Simulation Coupled with Three-dimensional Combustion Simulation

A Wireless Microwave Telemetry Data Transfer Technique for Reciprocating and Rotating Components

Wireless microwave telemetry addresses the difficult issue of obtaining transducer outputs from reciprocating and rotating components through the use of advanced electronic components. This eliminates the requirements of a direct link between the transducer and the acquisition system. Accuracy of the transducer signal is maintained through the use of a double frequency modulation technique which provides temperature stability and a 20 point calibration of the complete system. Multiple transmitters can be used for larger applications and multiple antennas can be used to improve the signal strength and reduce the possibility of dropouts. Examples of automotive torque converter and piston temperature measurements are provided, showing the effectiveness of the wireless measuring technique.

2414 火炎伝播を考慮したピストン非定常熱伝導解析(G07-2 エンジンシステム(2),21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

In this study, we investigated a method of estimating the piston temperature in reciprocating engines. The piston temperature is strongly affected by the cylinder temperature distribution and in-cylinder turbulence. For that reason, it is necessary to take into account the effects of cooling by the intake air flow, the process of the temperature rise due to combustion, in-cylinder flow, and the shape of the combustion chamber on flame propagation. We conducted a 3D combustion simulation that, took into account various phenomena such spark ignition, flame propagation, and cooling loss. The values of the gas temperature and heat, transfer coefficient on the piston surface found from this 3D combustion simulation were input as the boundary conditions of a non-steady-state heat conduction analysis. The piston surface temperature, internal temperature and heat, flow were then calculated. It was found that the tendency of the calculated temperature distribution agreed with that of the temperature distribution measured by the hardness method.

Numerical investigations of piston cooling using oil jet in heavy duty diesel engines

Thermal loading of diesel engine pistons has increased dramatically in recent years owing to applications of various technologies to meet low emission and high power density requirements. Control of piston temperatures by cooling of these pistons has become one of the determining factors in a successful engine design. The pistons are cooled by oil jets fired at the underside from the crankcase. Any excessive piston temperature rise may lead to engine seizure because of piston warping. However, if the temperature at the underside of the piston, where the oil jet strikes the piston, is above the boiling range of the oil being used, it may contribute to the generation of mist. This mist significantly contributes to the non-tailpipe emissions in the form of unburnt hydrocarbons (UBHCs). The problem of non-tailpipe emissions has unfortunately not been looked into so seriously, as the current stress of all automobile manufacturers is to meet the tailpipe emission legislative limits. A numerical model has been developed using finite element methods for studying the oil jet cooling of pistons and has been validated experimentally on a flat plate cooled by oil jet. Using numerical modelling, the heat transfer coefficient (h) at the underside of the piston is predicted. This predicted value of heat transfer coefficient significantly helps in selecting the correct oil type, oil jet velocity, oil jet diameter, and distance of oil nozzle from the underside of the piston. It also helps to predict whether the selected grade of oil will contribute to mist generation. Isotherms of the predicted temperature profiles in a production grade piston have been plotted.

Spectroscopic Sensing Via Dual-CladOptical Fiber

Many optical sensors can be simplified and improved through the use of dual-clad fiber (DCF). Here, the authors highlight two applications related to combustion: H2O vapor temperature measurements in a gas-turbine combustor (by direct absorption spectroscopy) and piston temperature measurements in a reciprocating engine (by fiber-Bragg-grating thermometry). For both applications, the DCF conveniently provides a single-mode light pitch and a multimode light catch coaxially and within a single fiber. Both applications benefit from the ease of alignment and the access to tight spaces, which comes from sensing through a single fiber port. In addition, both applications are improved in bi-directional mode: the former with an increased absorption in a double pass through the engine, and the latter by monitoring a reflection feature instead of a relatively weak-transmission feature. The authors discuss potential designs for DCF-based sensors in detail, including options for connecting both a light source and detector to one end of the DCF

Development of a multipiston temperature telemetry system using Bluetooth networks

The engines in vehicles today are smaller in size and lighter in weight but are still required to produce high output power. These characteristics have been found to induce thermal problems in the engine. In solving this thermal problem, temperature measurement in the piston of the engine plays an important role. However, owing to the environment of the piston, it is difficult to measure the temperature in the piston. Thus, developing a method to measure the temperature of the piston is currently an important research topic. This paper presents a piston temperature telemetry system that was developed using Bluetooth. This system is advantageous in that it makes it possible to measure multipiston temperature using a Bluetooth wireless network, which is an area that has yet to be investigated in more depth. The telemetry system is composed of the piston part and the data acquisition part. To evaluate the performance of the telemetry system, experiments were conducted using a 2359 cm31 DOHC engine produced by the Hyundai Motor Company. The experimental results show that the piston telemetry system is applicable to real commercial engines for measuring piston temperature.

A concise wall temperature model for DI Diesel engines

A concise resistor model for wall temperature prediction in diesel engines with piston cooling is presented here. The model uses the instantaneous in-cylinder pressure and some usually measured operational parameters to predict the temperature of the structural elements of the engine. The resistor model was adjusted by means of temperature measurements in the cylinder head, the liner and the piston. For each model parameter, an expression as a function of the engine geometry, operational parameters and material properties was derived to make the model applicable to other similar engines. The model predicts well the cylinder head, liner and piston temperature and is sensitive to variations of operational parameters such as the start of injection, coolant and oil temperature and engine speed and load.

The effect of piston bowl temperature on diesel exhaust emissions

In modern, high-speed, direct injection diesel engines for passenger vehicles, there is extensive impingement of the fuel sprays on to the piston bowl walls. Recent trends towards smaller engine sizes, equipped with high-pressure common-rail fuel injection systems, have tended to increase the spray/piston wall interaction. This paper describes tests carried out in a high-speed direct injection automotive diesel engine, during which the temperature of the piston was increased in a controlled manner between 189 and 227 °C while being continuously monitored. The aim of the work was to quantify the effects of piston temperature on pollutant exhaust emissions. The results show a significant reduction in unburned hydrocarbon emission, a significant increase in smoke emission, and no significant change in the emission of oxides of nitrogen. The increase in smoke emission cannot be ascribed to changes in the engine volumetric efficiency or air-fuel ratio. The paper demonstrates that fuel spray deposition on the piston surface was in the form of a thin film that did not experience bulk boiling. A number of suggestions are put forward to help explain the observed changes in exhaust emissions with increasing piston temperature.

In-situ piston measurements

Measurements are reported of piston secondary motion, piston ring motion, piston ring oil-film thicknesses, piston ring pack oil chemistry, piston friction and piston temperatures, using a variety of experimental techniques on running engines. These in-situ measurements have highlighted a number of interesting effects, of importance to both the piston designer and the lubricant formulator.