scholarly journals FINITE ELEMENT ANALYSIS OF THE HEAT TRANSFER IN A PISTON

2020 ◽  
Vol 4 (1) ◽  
pp. 45-51
Author(s):  
Aisha Muhammad ◽  
Shanono Ibrahim Haruna
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Numerical Simulations ◽  
Internal Combustion Engines ◽  
Thermal Stresses ◽  
Maximum Temperature ◽  
Cylinder Wall ◽  
Fe Model ◽  
Piston Cylinder ◽  
Piston Head

The gas expansion process that takes place in a piston cylinder assembly have been used in numerous applications. However, the time-dependent process of heat transfer is still not fully apprehended as the expansion processes are complex and difficult due to the unsteady property of the turbulent flow process. Internal combustion Engines(ICE) designs are conducted with the aim of achieving higher efficiency in the thermal characteristics. To optimize these designs, numerical simulations are conducted. However, modelling of the process in terms of heat transfer and combustion is complex and challenging. For a designer to understand, calculate and quantify the thermal stresses and heat losses at different sections of the structure, understanding the piston-cylinder wall is needed. This study carried out a numerical simulations based on Finite Element Method (FEM) to investigatethe stresses in the piston, and temperature after loading. Appropriate boundary conditions were set on different surfaces for FE model. The study includes the effects of the thermal conductivity of the material of piston, cylinder wall, and connecting rod. Results show the maximum Von-misses stress occurs on the piston head with a value of 3486. 1MPa. The maximum temperature of the piston head and cylinder wall stands at 68.252 and 42.704 degree Celsius respectively.

scholarly journals Experimental Thermal Analysis of Diesel Engine Piston and Cylinder Wall

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Subodh Kumar Sharma ◽  
P. K. Saini ◽  
N. K. Samria
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Wall Temperature ◽  
Thermal Loading ◽  
Thermal Stresses ◽  
Transfer Model ◽  
Cylinder Wall ◽  
Fe Model ◽  
Transfer Coefficients ◽  
Thermocouple Wire

Knowledge of piston and cylinder wall temperature is necessary to estimate the thermal stresses at different points; this gives an idea to the designer to take care of weaker cross section area. Along with that, this temperature also allows the calculation of heat losses through piston and cylinder wall. The proposed methodology has been successfully applied to a water-cooled four-stroke direct-injection diesel engine and it allows the estimation of the piston and cylinder wall temperature. The methodology described here combines numerical simulations based on FEM models and experimental procedures based on the use of thermocouples. Purposes of this investigation are to measure the distortion in the piston, temperature, and radial thermal stresses after thermal loading. To check the validity of the heat transfer model, measure the temperature through direct measurement using thermocouple wire at several points on the piston and cylinder wall. In order to prevent thermocouple wire entanglement, a suitable pathway was designed. Appropriate averaged thermal boundary conditions such as heat transfer coefficients were set on different surfaces for FE model. The study includes the effects of the thermal conductivity of the material of piston, piston rings, and combustion chamber wall. Results show variation of temperature, stresses, and deformation at various points on the piston.

scholarly journals Investigation of the Heat Transfer Process in Internal Combustion Engine Cylinders

2020 ◽  
pp. 266-274
Author(s):  
Volodumur Suvolapov ◽  
◽  
Andriy Novitskiy ◽  
Vasul Khmelevski ◽  
Oleksandr Bustruy ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Contact Layer ◽  
Internal Combustion ◽  
Temperature Fields ◽  
Cylinder Surface ◽  
Stationary Mode ◽  
Cylinder Wall ◽  
Engine Cylinder

The article analyzes scientific publications and literary studies of heat transfer processes in cylinders of internal combustion engines. The research of temperature fields in engines during their operation at different modes with the use of a software package and calculation module is presented. The results of modeling and thermo-metering in homogeneous and laminated engine cylinder liners are analyzed. Graphic dependencies and temperature distribution by cylinder wall thickness at maximum and minimum temperature on cylinder surface are given. On the basis of researches it is established that at laminating and pressing of inserts temperature fields in the engine cylinder change, temperature on an internal surface of the cylinder increases at laminating on 6,5 °С, and at pressing - on 4,5 °С. This is explained by the fact that the contact layer during plastification is in the zone of non-stationary mode, and when pressing the contact layer is in the zone of stationary mode and thus increases the thickness of the cylinder by 2 millimeters. It is established that the difference of minimum and maximum temperatures on the inner surface of the cylinder practically remains the same as that of a homogeneous cylinder. Thus, modeling becomes the most effective scientific tool in the development and implementation of long-term evaluation of options for improving ICE.

Modeling and simulation of frictional disc/pad interface considering the effects of thermo-mechanical coupling

2020 ◽  
Vol 17 (6) ◽  
pp. 761-784
Author(s):  
Ali Belhocine ◽  
Oday Ibraheem Abdullah
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Von Mises Stress ◽  
Brake Disc ◽  
Fe Model ◽  
Cooling Mode ◽  
Element Analysis ◽  
Content Type ◽  
Computational Fluid Dynamics Analysis ◽  
Brake Discs

Purpose This study aims to investigate numerically a thermomechanical behavior of disc brake using ANSYS 11.0 which applies the finite element method (FEM) to solve the transient thermal analysis and the static structural sequentially with the coupled method. Computational fluid dynamics analysis will help the authors in the calculation of the values of the heat transfer (h) that will be exploited in the transient evolution of the brake disc temperatures. Finally, the model resolution allows the authors to visualize other important results of this research such as the deformations and the Von Mises stress on the disc, as well as the contact pressure of the brake pads. Design/methodology/approach A transient finite element analysis (FEA) model was developed to calculate the temperature distribution of the brake rotor with respect to time. A steady-state CFD model was created to obtain convective heat transfer coefficients (HTC) that were used in the FE model. Because HTCs are dependent on temperature, it was necessary to couple the CFD and FEA solutions. A comparison was made between the temperature of full and ventilated brake disc showing the importance of cooling mode in the design of automobile discs. Findings These results are quite in good agreement with those found in reality in the brake discs in service and those that may be encountered before in literature research investigations of which these will be very useful for engineers and in the design field in the vehicle brake system industry. These are then compared to experimental results obtained from literatures that measured ventilated discs surface temperatures to validate the accuracy of the results from this simulation model. Originality/value The novelty of the work is the application of the FEM to solve the thermomechanical problem in which the results of this analysis are in accordance with the realized and in the current life of the braking phenomenon and in the brake discs in service thus with the thermal gradients and the phenomena of damage observed on used discs brake.

Finite Element Simulation of Steel Quench Distortion- Parametric Analysis of Processing Variables

2012 ◽  
Vol 1485 ◽  
pp. 29-34 ◽  
Author(s):  
F. A. García-Pastor ◽  
R.D. López-García ◽  
E. Alfaro-López ◽  
M. J. Castro-Román
Keyword(s):  
Finite Element ◽  
Martensitic Transformation ◽  
Internal Stress ◽  
Thermal Stresses ◽  
Stress Fields ◽  
Leaf Spring ◽  
Internal Stresses ◽  
Processing Temperature ◽  
Fe Model ◽  
Slow Cooling

ABSTRACTSteel quenching from the austenite region is a widely used industrial process to increase strength and hardness through the martensitic transformation. It is well known, however, that it is very likely that macroscopic distortion occurs during the quenching process. This distortion is caused by the rapidly varying internal stress fields, which may change sign between tension and compression several times during quenching. If the maximum internal stress is greater than the yield stress at given processing temperature, plastic deformation will occur and, depending on its magnitude, macroscopic distortion may become apparent.The complex interaction between thermal contraction and the expansion resulting from the martensitic transformation is behind the sign changes in the internal stress fields. Variations in the steel composition and cooling rate will result in a number of different paths, which the internal stresses will follow during processing. Depending on the route followed, the martensitic transformation may hinder the thermal stresses evolution to the point where the stress fields throughout the component may actually be reverted. A different path may support the thermal stresses evolution further increasing their magnitude. The cross-sectional area also affects the internal stresses magnitude, since smaller areas will have further trouble to accommodate stress, thus increasing the distortion. Additionally, the bainitic transformation occurring during relatively slow cooling rates may have an important effect in the final stress field state.A finite-element (FE) model of steel quenching has been developed in the DEFORM 3D simulation environment. This model has taken into account the kinetics of both austenite-bainite and austenite-martensite transformations in a simplified leaf spring geometry. The results are discussed in terms of the optimal processing parameters obtained by the simulation against the limitations in current industrial practice.

scholarly journals Comparisons of Global Heat Transfer Correlations for Conventional and High Efficiency Reciprocating Engines

2011 ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Heat Transfer ◽  
Nitric Oxide ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Cylinder Wall ◽  
Wall Heat Transfer ◽  
Engine Efficiency ◽  
Nitric Oxide Emissions ◽  
Heat Transfer Correlations ◽  
And Performance

Cylinder wall heat transfer is known to be an important process for internal combustion engines, and directly affects engine efficiency, performance and emissions. In some cases, up to third of the fuel energy is lost via heat transfer. Better understandings of the cylinder heat transfer should provide opportunities for improvements of engine efficiency and performance. The influence of various heat transfer correlations on engine efficiency and performance, total heat transfer and nitric oxide emissions is determined for conventional and high efficiency engines. These high efficiency engines are often based on “low temperature combustion” — and such engines have inherently lower heat transfer. At least some of the improvements associated with LTC engines are attributed to reduced heat losses. This work uses a thermodynamic engine cycle simulation and studies automotive engines. Both conventional and LTC engines are examined. As expected, engine performance and efficiency increase for reductions in the cylinder wall heat transfer. Although the heat transfer is lower for LTC engines compared to conventional engines, efficiency increases still are obtained as the cylinder wall heat transfer is reduced. In addition to the above, these assessments include the effects of the various heat transfer correlations on nitric oxide emissions and exergy destruction during the combustion process for both engines.

Explicit Finite Element Analyses of Drop Tests With Thin-Walled Steel Sheet Containers for the Konrad Repository

2015 ◽  
Author(s):  
Christian Protz ◽  
Uwe Zencker ◽  
Robert Liebich
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Damage Mechanics ◽  
Steel Sheet ◽  
Assessment Procedure ◽  
Fe Model ◽  
Explicit Finite Element ◽  
Safety Margins ◽  
Drop Tests ◽  
Thin Walled

Alternatively to experimental drop tests, the mechanical safety analyses of containers for final disposal of radioactive waste with negligible heat generation in the German Konrad repository may be carried out by numerical simulations within the safety assessment procedure. In the past, safety assessments for thin-walled steel sheet containers have been done exclusively by prototype tests and unfavorable drop scenarios were determined by engineering judgment. So far, reliable numerical simulations do not exist. Therefore, a research project was started to develop numerical simulation approaches for drop test analyses and to determine existing safety margins. Comparisons of experimental and numerical results confirm that the Finite Element (FE) model represents the general mechanical behavior of the steel sheet container sufficiently. Simulations have been used to determine an unfavorable drop scenario resulting in large deformation and damage. This paper presents the investigations carried out as well as the further development of the FE model in terms of damage mechanics.

Thermal Reliability Design and Optimization for Multilayer Composite Electronic Boards

2005 ◽  
Author(s):  
Amir Khalilollahi ◽  
Russell L. Warley ◽  
Oladipo Onipede
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Stress Intensity ◽  
Finite Element Model ◽  
Element Model ◽  
Fe Model ◽  
Transfer Coefficients ◽  
Thermal Reliability ◽  
Irreversible Damage ◽  
Heat Transfer Coefficients

Boards made of composites are susceptible of structural failure or irreversible damage under thermally raised stresses. A thermal/structural finite element model is integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board is modeled as a thin plate containing four heated flush rectangular areas that represent the electronic modules. The finite element model should be to able to accept the convection heat transfer on the board surface, heat generation in the modules, and directional conduction inside the board. A detailed 3-D CFD model is incorporated to predict the conjugate heat transfer coefficients that strongly affect the temperature distribution in the board and modules. Structural analyses are performed by a FE model that uses the heat transfer coefficients mentioned above, and structural elements capable of handling orthotropic material properties. The stress fields are obtained and studied for the models possessing two and there laminates with different fiber orientations, and inter-fiber angles. Appreciable differences in values of max stress intensity were observed as the fiber orientation and inter-fiber angle changed. The angular parameters in this study were guided by experimental design (DOE) concepts leading to a metamodel of the stress intensity in the board. The optimum design variables found by the equations of the metamodel.

Design of Flexible Multi-Gripper Stretch Forming Machine by FEM

2011 ◽  
Vol 328-330 ◽  
pp. 13-17 ◽  
Author(s):  
He Li Peng ◽  
Mine Zhe Li ◽  
Qi Gang Han ◽  
Peng Xiao Feng ◽  
Hao Han Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Simulations ◽  
Simple Structure ◽  
Metal Sheet ◽  
Fe Model ◽  
Stretch Forming ◽  
Double Curvature ◽  
Better Than

In order to improve the performance of back drawing type of flexible multi-gripper stretch forming machine used for double-curvature metal sheet forming, back and down drawing type of flexible multi-gripper stretch forming machine was designed by finite element method (FEM), which has simple structure and cheap cost. The FE model of flexible multi-gripper stretch forming was established, and extensive numerical simulations of spherical parts for two kinds of flexible stretch forming machines were carried out. The variations of stress, strain, thickness and springback value of spherical parts for two kinds of drawing modes were analyzed. The numerical results show that the quality of spherical parts formed by the back and down drawing type of stretch forming machine is better than that by the back drawing type of stretch forming machine. This work provides a machine for developing the technology of stretch forming.

Thermomechanical Stresses in Copper Interconnect/Low-κ Dielectric Systems

2004 ◽  
Vol 812 ◽  
Author(s):  
Y.-L. Shen ◽  
E. S. Ege
Keyword(s):  
Finite Element ◽  
Metal Oxide ◽  
Numerical Simulations ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Deformation Pattern ◽  
Barrier Layers ◽  
Copper Interconnect ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

AbstractNumerical simulations of thermal stresses in copper interconnect and low-κ dielectric systems are carried out. The analyses include two- and three-dimensional finite element modeling of the interconnect structure. Various combinations of metal, oxide and polymer-based low-κ dielectric schemes are considered in the simulation. The evolution of stresses and deformation pattern in copper, barrier layers, and the dielectrics are critically assessed.

scholarly journals Analysis of Combined Convection in an Open Cavity under Constant Heat Flux Boundary Conditions and Magnetic Field Using Finite Element Method

2014 ◽  
Vol 6 (2) ◽  
pp. 243-256 ◽  
Author(s):  
A. Kalam ◽  
J. H. Munshi ◽  
M. Rahman ◽  
M. M. K. Chowdhury
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Aspect Ratio ◽  
Boundary Conditions ◽  
Length Change ◽  
Constant Heat Flux ◽  
Open Cavity ◽  
Maximum Temperature ◽  
Fluid Temperature ◽  
Rayleigh Numbers

This study investigated the effects of the aspect ratio of the cavity for average fluid temperature at exit port, average Nusselt number, maximum temperature of the fluid in the domain, drag coefficient, isotherms and streamlines on behalf of different Hartmann numbers and Rayleigh numbers. Solution of governing equations of momentum and energy has been made by finite element technique. Above mentioned parameters such as an aspect ratio which is cavity height to cavity length change from Ar = 0.5 to 2 for different Rayleigh numbers and Hartmann numbers which change from Ra = 103 to 105 and Ha = 0 to 50 respectively. Prandtl number Pr = 7 and Reynolds number Re = 100 is fixed in this simulation. It is found that variation of the aspect ratio makes an important effect for higher values of Rayleigh numbers. Heat transfer enhances with increasing of aspect ratio. Increasing of Hartmann number decreases the heat transfer inside the cavity.  Keywords: Temperature boundary conditions; Open cavity; Aspect ratio; Finite element methods.  © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  doi: http://dx.doi.org/10.3329/jsr.v6i2.14505 J. Sci. Res. 6 (2), 243-256 (2014)

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