The Simulation Optimization and Experimental Improvement of the Refrigerator

2014 ◽  
Vol 1051 ◽  
pp. 840-844
Author(s):  
Ya Le Zhao ◽  
Fang Wang ◽  
Jia Wen Zhang ◽  
Ding Ding Yang ◽  
Tang Li ◽  
...  
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Posterior Wall ◽  
Calculation Model ◽  
Alternative Refrigerant ◽  
Environment Friendly ◽  
Distribution Scheme ◽  
Experimental Improvement ◽  
Better Than

The Chinese refrigeration industry is faced with dual pressure of energy saving and emission reduction. R600a as an alternative refrigerant of R134a is environment friendly, and the alternation is very good. Firstly, this paper established a two-dimensional steady numerical calculation model of the refrigerating chamber with R600a, and studied the influence of the temperature distribution of the refrigerator’s posterior wall under different schemes on temperature field and velocity field of the refrigerating chamber. When the function of temperature distribution is T=-11.75*y, will achieve the best temperature field and velocity field, and the results are better than the original machine. Secondly, this paper studied the experimental improvement of R600a under the best temperature distribution scheme comparing with R134a.

Simulation of Concrete in Winter with Self-Limiting Heating Band

2022 ◽  
Vol 905 ◽  
pp. 297-302
Author(s):  
Lin Liu ◽  
Mei Qing Zhang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Analytical Calculation ◽  
Heating Zone ◽  
Surface Layout ◽  
Combined Action ◽  
Early Age Concrete ◽  
Cracking Risk ◽  
Concrete Component ◽  
Better Than

In order to investigate the temperature distribution and cracking risk of concrete in winter under the combined action of heating zone and air layer, the analytical calculation method of early age concrete temperature field of concrete component under the combined action of self-limiting temperature band, cement hydration and air layer was established by taking concrete prism with self-limiting temperature band as an example. The model is applied to calculate and analyze the temperature distribution of concrete under different boundary conditions and different additional thermal field modes. The results show that: Under the conditions of internal layout, surface layout and thermal insulation layer outside the formwork, all components reach the critical strength after heating and curing for three days, which indicates that the heating band can provide temperature conditions for concrete curing in winter. Comparing the temperature field of different layout positions of heating belt, the uniformity of temperature field of heating belt outside the formwork is better than the other two layout methods.

scholarly journals Finite-Element Simulation of the Thermal Regime of the Erebus Glacier Tongue, Antarctica

1986 ◽  
Vol 32 (112) ◽  
pp. 530-534
Author(s):  
D.F.E. Stolle ◽  
F.A. Mirza
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Steady State ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Thermal Regime ◽  
Short Term ◽  
Glacier Tongue ◽  
Element Simulation

AbstractFinite-element method is used to determine the temperature distribution within the Erebus Glacier tongue based on information from short-term observations (Holdsworth, 1982). It is shown that, provided the up-stream temperature profile along the depth is known, steady-state assumptions are reliable for computing the temperature field within most of the ice mass at any given time for a glacier tongue. Numerical results from analyses of the Erebus Glacier tongue also indicate that the main transport of heat is through advection as expected and, hence, a realistic estimate of the velocity field becomes important.

scholarly journals Finite-Element Simulation of the Thermal Regime of the Erebus Glacier Tongue, Antarctica

1986 ◽  
Vol 32 (112) ◽  
pp. 530-534
Author(s):  
D.F.E. Stolle ◽  
F.A. Mirza
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Steady State ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Thermal Regime ◽  
Short Term ◽  
Glacier Tongue ◽  
Element Simulation

AbstractFinite-element method is used to determine the temperature distribution within the Erebus Glacier tongue based on information from short-term observations (Holdsworth, 1982). It is shown that, provided the up-stream temperature profile along the depth is known, steady-state assumptions are reliable for computing the temperature field within most of the ice mass at any given time for a glacier tongue. Numerical results from analyses of the Erebus Glacier tongue also indicate that the main transport of heat is through advection as expected and, hence, a realistic estimate of the velocity field becomes important.

Numerical Simulation of Solidification Process for a Machine Tool Bed

2011 ◽  
Vol 675-677 ◽  
pp. 987-990
Author(s):  
Ling Tang ◽  
Xu Dong Wang ◽  
Hai Jing Zhao ◽  
Man Yao
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Machine Tool ◽  
Computation Time ◽  
Solidification Process ◽  
Field Calculation ◽  
Original Design ◽  
Calculation Results ◽  
Improved Design

In this paper, the flow, heat transfer and stress during solidification process of the machine tool bed weighed about 2.5ton that has been optimized by structural topologymethod, was calculated with ProCAST software, and the causes of the crack forming in the casting of the machine tool bed was analysed. According to the calculation results, the structural design of the local part where cracks tends to form has been improved, and the heat transfer and the stress are calculated again. By comparing the temperature field with filling of molten cast iron and without filling, it has been found that there was little effect of filling on the results of temperature distribution of the cast, therefore the effect of filling can be ignored in the following temperature field calculation to save computation time. The model has been simplified in the stress field calculation with considering the complexity of the machine tool bed and the cost of computation. Then, the merits and demerits of the original design and the improved design are compared and analyzed depending on the calculated temperature and stress results. It is suggested that the improved one could get a more uniform temperature distribution and then the trend of the crack occurring can be greatly reduced. These results could provide a guide for the actual casting production, achieving the scientific control of the production of castings, ensuring the quality of the castings.

Influence of rotating magnetic field on Maxwell saturated ferrofluid flow over a heated stretching sheet with heat generation/absorption

2019 ◽  
Vol 20 (5) ◽  
pp. 502 ◽  
Author(s):  
Aaqib Majeed ◽  
Ahmed Zeeshan ◽  
Farzan Majeed Noori ◽  
Usman Masud
Keyword(s):  
Magnetic Field ◽  
Temperature Field ◽  
Velocity Field ◽  
Differential Equations ◽  
Heat Transport ◽  
Viscous Dissipation ◽  
Heat Generation ◽  
Fluid Motion ◽  
Numerical Procedure ◽  
The Impact

This article is focused on Maxwell ferromagnetic fluid and heat transport characteristics under the impact of magnetic field generated due to dipole field. The viscous dissipation and heat generation/absorption are also taken into account. Flow here is instigated by linearly stretchable surface, which is assumed to be permeable. Also description of magneto-thermo-mechanical (ferrohydrodynamic) interaction elaborates the fluid motion as compared to hydrodynamic case. Problem is modeled using continuity, momentum and heat transport equation. To implement the numerical procedure, firstly we transform the partial differential equations (PDEs) into ordinary differential equations (ODEs) by applying similarity approach, secondly resulting boundary value problem (BVP) is transformed into an initial value problem (IVP). Then resulting set of non-linear differentials equations is solved computationally with the aid of Runge–Kutta scheme with shooting algorithm using MATLAB. The flow situation is carried out by considering the influence of pertinent parameters namely ferro-hydrodynamic interaction parameter, Maxwell parameter, suction/injection and viscous dissipation on flow velocity field, temperature field, friction factor and heat transfer rate are deliberated via graphs. The present numerical values are associated with those available previously in the open literature for Newtonian fluid case (γ 1 = 0) to check the validity of the solution. It is inferred that interaction of magneto-thermo-mechanical is to slow down the fluid motion. We also witnessed that by considering the Maxwell and ferrohydrodynamic parameter there is decrement in velocity field whereas opposite behavior is noted for temperature field.

An analytical solution of a two-dimensional temperature field in a hollow cylinder under a time periodic boundary condition using Fourier series

2009 ◽  
Vol 223 (8) ◽  
pp. 1889-1901 ◽  
Author(s):  
G Atefi ◽  
M A Abdous ◽  
A Ganjehkaviri ◽  
N Moalemi
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Fourier Series ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Hollow Cylinder ◽  
Periodic Boundary Condition ◽  
Periodic Boundary ◽  
Separation Of Variables ◽  
Two Dimensional

The objective of this article is to derive an analytical solution for a two-dimensional temperature field in a hollow cylinder, which is subjected to a periodic boundary condition at the outer surface, while the inner surface is insulated. The material is assumed to be homogeneous and isotropic with time-independent thermal properties. Because of the time-dependent term in the boundary condition, Duhamel's theorem is used to solve the problem for a periodic boundary condition. The periodic boundary condition is decomposed using the Fourier series. This condition is simulated with harmonic oscillation; however, there are some differences with the real situation. To solve this problem, first of all the boundary condition is assumed to be steady. By applying the method of separation of variables, the temperature distribution in a hollow cylinder can be obtained. Then, the boundary condition is assumed to be transient. In both these cases, the solutions are separately calculated. By using Duhamel's theorem, the temperature distribution field in a hollow cylinder is obtained. The final result is plotted with respect to the Biot and Fourier numbers. There is good agreement between the results of the proposed method and those reported by others for this geometry under a simple harmonic boundary condition.

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

2021 ◽  
Vol 21 (11) ◽  
pp. 293
Author(s):  
Shan-Xiang Wei ◽  
De-Qing Kong ◽  
Qi-Ming Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Radio Telescope ◽  
Thermal Imaging ◽  
Uniform Temperature ◽  
Large Radio Telescope ◽  
Uniform Temperature Distribution ◽  
Uniform Temperature Field ◽  
Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

scholarly journals Investigation on the Non-Uniform Temperature Distribution of Large-Diameter Concrete Silos under Solar Radiation

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Liang Zhao ◽  
Zhiyong Yang ◽  
Lijie Wang
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Temperature Distribution ◽  
Temperature Effects ◽  
Large Diameter ◽  
Fe Model ◽  
Concrete Walls ◽  
Steady State Method ◽  
Nonlinear Temperature ◽  
Internal Forces

There is a growing demand for silos with large diameters and volumes; hence, the stresses induced by the temperature differences between the inner and the outer surfaces of the concrete walls of the large silos become significant. Sunshine is the main source of the temperature differences; and it is necessary to investigate the influences of sunshine on large concrete silos and ensure their safety and durability. In this paper, the temperature distribution of a concrete silo exposed to the sunshine was measured on site. A finite element (FE) model was built to analyze the temperature distribution under the sunshine, and the FE model was validated by comparing the yielded temperature field with that obtained on site. Based on the temperature field yielded in the FE model, the internal forces of the silo were determined by performing a structural analysis. After that, the FE model was extended and used for a parametrical study, and the influences induced by the factors like meteorological parameters, dimension of silos, and reference temperature on the temperature effects of the silo were investigated. The simulation results showed that the temperature gradient exhibited significant nonlinearities along the wall thickness. The performance of a steady-state analytical method was evaluated, which is conventionally used for the design of silos. It was found that, for the silos with the thicknesses of more than 30 centimeters, the steady-state method overestimated the temperature effects. It is suggested here that nonlinear temperature gradients should be employed for considering the temperature effects of large silos.

Analytical Modeling of Temperature Distribution in Interposer-Based Microelectronic Systems

2013 ◽  
Author(s):  
Leila Choobineh ◽  
Dereje Agonafer ◽  
Ankur Jain
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Analytical Modeling ◽  
Three Dimensional ◽  
Heat Transfer Process ◽  
Thermal Design ◽  
Research Attention ◽  
On Chip

Heterogeneous integration in microelectronic systems using interposer technology has attracted significant research attention in the past few years. Interposer technology is based on stacking of several heterogeneous chips on a common carrier substrate, also referred to as the interposer. Compared to other technologies such as System-on-Chip (SoC) or System-in-Package (SiP), interposer-based integration offers several technological advantages. However, the thermal management of an interposer-based system is not well understood. The presence of multiple heat sources in various die and the interposer itself needs to be accounted for in any effective thermal model. While a finite-element based simulation may provide a reasonable temperature prediction tool, an analytical solution is highly desirable for understanding the fundamentals of the heat transfer process in interposers. In this paper, we describe our recent work on analytical modeling of heat transfer in interposer-based microelectronic systems. The basic governing energy conservation equations are solved to derive analytical expressions for the temperature distribution in an interposer-based microelectronic system. These solutions are combined with an iterative approach to provide the three-dimensional temperature field in an interposer. Results are in excellent agreement with finite-element solutions. The analytical model is utilized to study the effect of various parameters on the temperature field in an interposer system. Results from this work may be helpful in the thermal design of microelectronic systems containing interposers.

Analysis of Temperature Field Based on Hollow Sucker Rod Hot Flushing Technology

2014 ◽  
Vol 1073-1076 ◽  
pp. 2257-2262
Author(s):  
Jie Yu Du ◽  
Jiang Xie ◽  
Yu Qi Zhao ◽  
Li Peng Zhang ◽  
Rui Bin Zhu
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Low Pressure ◽  
Calculation Model ◽  
Simulation System ◽  
Well Production ◽  
Transfer Theory ◽  
Heat Transfer Theory ◽  
Sucker Rod ◽  
Theory Calculation

The hot flushing is a major means of removing wax. For low pressure reservoir, it is possible to produce a large number of washing fluid flowing into the formation, which affects the well production recovery. The application of hollow sucker rod hot flushing technology can avoid fluid pouring back into the formation, and the wells can keep production. Based on the principle of hollow sucker rod hot flushing and heat transfer theory, calculation model of temperature field was established, and hollow sucker rod hot flushing simulation system was developed, which can guide flushing in oilfield.

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