Thermal Load Analysis of Piston in a Biogas Engine

2011 ◽  
Vol 63-64 ◽  
pp. 1005-1008
Author(s):  
Yi Wu ◽  
Yi Qiang Peng ◽  
Chong Huai Shi

As a kind of new renewable energy, biogas is receiving more and more attentions. However, its combustion duration is longer than diesel, which causes the bigger thermal load of engine. A geometry model of a biogas engine’s piston is set up in Proe 4.0. The temperature fields, thermal stress and thermal deformation of the piston are calculated using ANSYS 10.0. The result shows that the thermal load of biogas engine is still within the thermal strength of the material, thus provides supporting evidence for the popularity of biogas.

2011 ◽  
Vol 199-200 ◽  
pp. 1192-1195
Author(s):  
Jing Yang ◽  
Yi Wang ◽  
Ming Wei Xiao

The piston is a key part of engine,working in high temperature,high pressure and high load of harsh environment;Besides, periodic mechanical load and heat load work on it.Firstly,use the software UG to set up a geometry model of the piston;then use the ANSYS to set up finite element modle.We can learn about the total deformation with thermal load so as to find out the dangerouse and thermal stress points and provide theory for improving and optimizing structure of piston after mechanical load is added to the piston and coupling analysis is carried out.


2014 ◽  
Vol 602-605 ◽  
pp. 610-613
Author(s):  
Xiao Yu Jin ◽  
Jin Jun Tang ◽  
Li Qun Hou ◽  
Yu Lei Li ◽  
Qun Wang

To solve the thermal load problem of 1015 engine cylinder liner, based on the temperature field measured, the boundary condition of 1015 engine cylinder liner was determined, a comparatively perfect mathematic mode and a geometric model are built up, and the analysis of the three dimension temperature field of cylinder liner and the thermal deformation was performed using FEA method.


Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Shengzhe Ji ◽  
Wenfa Huang ◽  
Tao Feng ◽  
Long Pan ◽  
Jiangfeng Wang ◽  
...  

In this paper, a model to predict the thermal effects in a flashlamp-pumped direct-liquid-cooled split-disk Nd:LuAG ceramic laser amplifier has been presented. In addition to pumping distribution, the model calculates thermal-induced wavefront aberration as a function of temperature, thermal stress and thermal deformation in the gain medium. Experimental measurements are carried out to assess the accuracy of the model. We expect that this study will assist in the design and optimization of high-energy lasers operated at repetition rate.


2021 ◽  
pp. 1-13
Author(s):  
Zheng Li ◽  
B.L. Wang ◽  
Kaifa Wang

Abstract Thermal shock multiple cracking behaviors of re-entrant auxetic honeycombs with a negative Poisson's ratio are investigated, and the crack initiation and propagation behavior are discussed. An effective macro continuum model is developed to detect the effects of cracking density and microstructures of auxetic honeycombs on the thermal stress and intensity. The microscale tensile stresses in the struts ahead of the crack as functions of the corresponding thermal stress intensity factor (SIF) at the macroscale are evaluated by employing a macro-micro model. Then, a lower-bound method is proposed to assess the critical thermal load of auxetic honeycombs by combining the macro-micro model and the macro continuum model. A significant increase in both transient thermal stress and intensity as the growing cell-wall angle is demonstrated. Results for the maximum thermal SIF as well as the maximum tensile stress in the middle of cracks are calculated as functions of crack density and length. With the identical SIF, the microscale tensile stresses ahead of the crack in honeycombs with smaller cell-wall angles are greater than that in mediums with larger angles due to the more significant crack tip opening displacement. Critical thermal load prediction reveals that the honeycombs with smaller cell-wall angles generally possess more excellent thermal shock resistance. Also, the varying failure modes of different auxetic honeycomb strips under specific thermal load are predicted. The corresponding crack initiation and propagation mechanisms are revealed.


2014 ◽  
Vol 18 (5) ◽  
pp. 1607-1611 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Wei-Dong Song ◽  
Hui-Ping Tang ◽  
Zhi-Hua Wang ◽  
Long-Mao Zhao

Temperature field and thermal deformation of sandwich panels with closed-cell aluminum alloy foam core and heat-protective layer, which are subjected to Gaussian laser beam intensively irradiating, are investigated numerically. In transient heat analysis models, the influence of thermal conductivity, specific heat, and thickness of heat-protective layer on the temperature rise of the sandwich panels is calculated. In stress analysis models, a sequence coupled numerical method is utilized to simulate the thermal stress and deformation of sandwich panels induced by thermal expansion. Simulation results indicate that the temperature at center of sandwich panel increases firstly and then drops gradually with the increase of thermal conductivity of heat-protective layer after laser irradiation, and the critical thermal conductivity is obtained, while it decreases with the increase of specific heat and thickness of heat-protective layer. The thermal stress verifies the ?Cyclo-hoop effect?, i. e. radial stress is compression stress in ?hot zone? and tension stress in ?cold zone?. The max thermal deformation of sandwich panels slightly increases with the increase of thickness of heat-protective layer for given specific heat and thermal conductivity.


2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.


2013 ◽  
Vol 278-280 ◽  
pp. 500-504
Author(s):  
Shu Jie Zhang ◽  
Yu Han Zhang

Cyclic changes of temperature in space may cause thermal deformation and thermal stresses at the silver welding spots on solar cells, which result in the solar array work abnormally. According to the temperature conditions in the thermal vacuum, the thermal stress and deformation at silver welding spot that between solar cell and inter-link chip were analyzed. The result shows that thermal cycling can make the sliver welding spot separated or contacted, which cause the solar array work wrong. The phenomenon of thermal vacuum reliability test was corresponding with these results. This paper could offer some references for the design and manufacture of solar array in the future.


Author(s):  
Cao Qing ◽  
Wu Yimin ◽  
Zhang Zhimin

In this paper, a heat conduction equation and a dynamic thermoelastic equation are briefly deduced and established based on Continuum Mechanics. First, an qualitative discussion is emphatically centered around the couple term and the dynamic term of the equation by means of the dimensional analysis and by considering the combination of the characteristics of the materials and of the thermal load effected on the nuclear power station pump under study. Second, formulations of the FEM for non-coupled heated equations and quasi-static thermoelastic equations are derived in this paper. Third, a half space thermal shock problem is used as a computational example in the highlighted research on the varying behavior of the dynamic thermal stress on the temperature slope. The conclusion of the paper provides reliable justification for applying the numerical method. Finally, the distribution and variety of the temperature field, the thermal stress field and the thermal deformation field at various transient moments on the pump are given.


Sign in / Sign up

Export Citation Format

Share Document