Papers by Keyword: Temperature Field

Abstract: The paper took the piston of 620 single-cylinder engine as an example,a finite element model of piston was built with the help of ANSYS software. Than to calculate temperature field and and quick cold start conditions respectively^[1]. Through the periodic transient thermal analysis, temperature fluctuations on the surface of the piston were derived, which indicated that the surface contacted with gas was the main temperature fluctuation area. The max temperature fluctuation can be up to 20 ° C and the wild fluctuation occurred in a distance of 2 mm from the surface of the piston. Temperatures of the piston went up according to exponential rule during the course of quick cold start, Extreme temperature fluctuations will generate huge quasi-static thermal stress.

Abstract: Western Bei II Area in Saertu Oilfield, Daqing Oilfield is the test area. It has now entered an exploitation phase of extra high water cut stage. Under the circumstance of a long time of development and complex conditions of well history in this area, it has experienced water flooding, polymer flooding and thermal recovery. Based on basic geological characteristics in the test area, this study establishes three-dimensional geological static models and conducts the fine reservoir numerical simulation of the test area. In addition, it summarizes the temperature field distribution features before and after the thermal recovery as well as causes and distribution laws of the residual oil, which provides a reliable basis for development, deployment and measures to adjust in the next step in oilfields.

Abstract: In order to reveal the breakage mechanism of flat end mill under periodic thermal shock, transient temperature field model of chisel edge were established by heat source method, transient temperature field model of side edge were established along the sliced differential elements from the bottom of the flute toward the final axial depth of cut by means of line heat source. The simulation results show that transient temperature field prediction model can be used for prediction transient temperature field in high speeding.

Abstract: In order to reduce the wear of parts caused by long-term friction, and to reduce the frequency of parts replacement, ZA alloy with low hardness and good wear resistance is chosen to replace the traditional copper alloy as the material to manufacture automotive bushing, and the semi-solid die casting is used. On this basis, the software AnyCasting is used to simulate and analyze the filling and solidification process, the filling sequence, the variation of temperature field, and the part region where defects are prone to occur in the semi-solid process. The simulation results show that under the parameters set in the simulation process, when casting filling rate reached 90%, the metal started to solidify; since the gate place is easy for heat dissipation, when the temperature of the alloy liquid reached its liquidus temperature 595°C, the phenomenon of solid-liquid phase separation appeared at the gate; the defects such as gas trapping, residual stress and deformation would appear both in the place of first filling and the parting surface; when the preheat temperature of the mold was 150°C-200°C,the alloy liquid possesses liquidity. The simulation results offer certain theoretical instruction to optimize the semi-solid casting process of ZA Alloy automotive bushing manufacturing, as well as reducing or avoiding a variety of quality defects arose in the actual casting process.

Abstract: The thawing settlement related problems in 109^th national highway in Qinghai province were analyzed in this paper, experiment tests were conducted to investigate the behavior of subgrade under dynamic loading during thawing, a numerical simulation for the tests were also conducted. Both the tested and simulated results were analyzed and summarized.

Abstract: With fire temperature rising, elastic modulus of steel would be reduce, which then would lead to global instability phenomenon of double-layer square pyramid silo-shell structure. In order to analyze its fire resistance performance under high fire temperature, different geometric parameters were set based on the effect factors when it operated normally at room temperature. To analyze its displacement change by conducting nonlinear finite element analysis which was under the two typical temperature rising cases including global non-uniform temperature and localized high temperature. Then, with the temperature rising, the fire resistance performance and the maxium displacement changing rule were obtained.

Abstract: Under the high temperature of fire, the temperature change of the reinforced concrete beam is very important to the structure study. This paper, with heat transfer theory as its theoretical basis, explores the analytical method, the common method for analysis, calculation method of numerical value and finite element analysis by analyzing the temperature field of the concrete component cross sections under high temperature. With the help of MATLAB, it calculates and analyzes the temperature field of the reinforced concrete beam under the high temperature of fire, determines the temperature rise curve of the reinforced concrete beam in case of fire, and calculates the cross section temperature fields of the beam or pillar under the circumstances of different cross section sizes and different timings of fire on three sides.

Abstract: In this paper, the temperature fields of concrete specimens reinforced by paste method were analyzed by experiment and ANSYS in the fire, it proved that the impact of reinforcement material on the temperature field of the specimens can be ignored, it identified that the best thickness of the fire-retardant coating is 40mm for steel-confined specimens and 50mm for CFRP-confined specimens. The calculations agreed well with the experimental results, it provides conditions for mechanical properties of the concrete reinforced by paste method at high temperature.

Abstract: According to the mass and energy conservation principle of simulation program TOUGH2 used for non-isothermal multi-phase fluid and heat flow in porous and fractured media, the heat transport mathematical model of low-temperature shallow geothermal system is set up in homogeneous porous medium. The fundamental scientific issues on heat transfer characteristics and distribution of transient temperature field of heat exchange wells in summer is discussed in this paper. In addition, the significance and correlation between the changes of hydrogeology parameters and temperature field of the soil is analyzed. So as to the practical application of geothermal energy development can be guided by the achievements of the research.

Abstract: The paper analyzed the temperature field, the thermal stress field and the stress field under mechanical loads of a diesel engine cylinder head with finite element analysis software ANASYS, then took above temperature field results and mechanical loads as boundary conditions to impose on the established model of cylinder head using the thermal mechanism indirect coupled method, researched the stress field and distortion of cylinder head under effect of multiplicative loads. The result indicates that the point of the highest temperature and the maximum thermal stress locates on the middle nose of fire deck; under thermal mechanism coupled effect, the points of maximum stress locate on the interface of bolt head and screw of cylinder head and on the middle nose of fire deck; the maximum pull stress the cylinder head undertook is less than that the material can survive; the distortion of the cylinder head is very small, thus has little influence on the fabrication of other accessories, and the global distortion of cylinder head performs symmetry.