A Simulation Model to Calculate Temperature Distribution of an Air-Conditioned Room

2016 ◽  
Author(s):  
Ping Fang ◽  
Tingzhang Liu ◽  
Kai Liu ◽  
Yingqi Zhang ◽  
Jianfei Zhao
Keyword(s):  
Temperature Distribution ◽  
Simulation Model ◽  
Calculate Temperature Distribution

Numerical Simulation Model of Electrothermal De-Icing Process on Composite Substrate

2020 ◽  
Author(s):  
Xiaofeng Guo ◽  
Zhiqiang Guo ◽  
Qian Yang ◽  
Wei Dong
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Melting Process ◽  
Ice Melting ◽  
Melted Zone ◽  
Composite Substrate ◽  
Cfrp Composite

Abstract A numerical simulation model of electrothermal de-icing process on carbon fiber reinforced polymer (CFRP) composite is conducted to study the effect of thermal properties of the substrate on the ice melting process. A novel melting model which is based on the enthalpy-porosity method is applied to study the transient ice melting process and heat transfer of the de-icing sys-tem. Multi-layered electrothermal de-icing systems including composites with different fiber orientation are used to analyze the effects of orthotropic heat conductivity of the CFRP composite on the ice melting process and heat transfer. Movement of the ice-water interface, the melted zone thickness and the melted zone area on CFRP composite are investigated on the three-dimensional electrothermal de-icing unit. The effects of thermal properties of substrate on the temperature distribution of the ice-airfoil interface are analyzed. The computational results show that the thermal properties of substrates affect the temperature on the ice-airfoil interface, the temperature distribution in the substrate, ice melting area, ice melting rate and ice melting volume significantly. The time that ice starts to melt on the CFRP composite substrate is earlier than that on the metal substrate. However, it takes more time for the ice to melt completely on the ice-CFRP interface than that on the ice-metal inter-face. The orthotropic heat conductivity of CFRP composite results in strong directivity of the melting area on the ice-CFRP in-terface. A ratio parameter is defined to represent the matching degree of substrate materials and geometry model of de-icing system. The simulation model can be applied to study electrothermal de-icing system of nacelle inlet and airfoil made of composite. The results in present work is also helpful to predict the change of temperature during de-icing process and provide guidelines for the optimizing the electrothermal de-icing system to reduce power consumption according to the fiber structure of composite.

scholarly journals Modeling the Blow-Blow Forming Process in Glass Container Manufacturing: A Comparison Between Computations and Experiments

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
C. G. Giannopapa ◽  
J. A. W. M. Groot
Keyword(s):  
Computer Simulation ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Glass Container ◽  
Glass Temperature ◽  
Computer Simulation Model ◽  
Forming Process ◽  
Glass Thickness ◽  
Glass Containers ◽  
Container Manufacturing

The blow-blow forming process is a widely used technique in glass container manufacturing (e.g., production of glass bottles and jars). This process typically takes few seconds and is characterized by large deformations and temperature gradients. In the work of Giannopapa (2008, “Development of a Computer Simulation Model for Blowing Glass Containers,” ASME J. Manuf. Sci. Eng., 130, p. 041003), the development of a computer simulation model for glass blowing was presented and demonstrated on dummy problems with an initially uniform glass temperature. The objective of this paper is to extend and further develop the simulation model to be used for industrial purposes. To achieve this, both steps of the blow-blow forming process of glass containers are simulated and tested against real industrial problems. In this paper, a nonuniform temperature distribution is considered for the blowing of the preform, which is reconstructed from temperature data provided by the industry. The model is validated by means of several examples regarding conservation properties, behavior of the flow, and comparison of the glass thickness with experimental measurements. Furthermore, by means of these examples, the sensitivity of the glass thickness to inaccuracies in the measurement and reconstruction of the initial temperature distribution is verified.

An Experimental Study of Steam-Solvent Coinjection for Bitumen Recovery Using a Large-Scale Physical Model

SPE Journal ◽  
1900 ◽  
pp. 1-18
Author(s):  
Kai Sheng ◽  
Ryosuke Okuno ◽  
Abdullah Al-Gawfi ◽  
Petro Nakutnyy ◽  
Muhammad Imran ◽  
...  
Keyword(s):  
Experimental Data ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Physical Model ◽  
Material Balance ◽  
Cocurrent Flow ◽  
Internal Diameter ◽  
Asphaltene Content ◽  
Bitumen Recovery

Summary In this paper, we present a solvent-assistedsteam-assisted gravity drainage (SA-SAGD) experiment with multicomponent solvent (i.e., condensate) using a large physical model. The sandpack for the experiment had a porosity of 0.33 and a permeability of 5.6 darcies in the cylindrical pressure vessel that was 1.22 m in length and 0.425 m in internal diameter. The sandpack was initially saturated with 93% Athabasca bitumen and 7% deionized water. The main objective of this research was to study the in-situ thermal/compositional flow and produced bitumen properties in SA-SAGD with condensate. After the preheating of the sandpack for 24 hours, SA-SAGD with 2.8-mol% condensate was performed at 50 cm3/min (cold-water equivalent) at 3500 kPa for 3 days. The experimental data of production, injection, and temperature distribution were recorded. Also, 10 samples of produced oil were taken and analyzed for density and asphaltene content. The sandpack was excavated after the experiment to analyze the asphaltene content in the remaining oil at different locations. A numerical simulation model was calibrated based on the data of material balance and temperature distribution, and it was validated with properties of the produced and excavated samples. The simulation model used fluid models based on experimental data of viscosities, densities, and bubblepoints for four condensate/bitumen mixtures. Results showed that SA-SAGD was efficient in bitumen recovery with a cumulative steam-to-oil ratio (SOR) that was two to three times smaller than that in SAGD using the same physical model. Detailed analysis of the calibrated simulation model indicated that SA-SAGD enabled the steam chamber to expand more efficiently with a smaller amount of water throughput than SAGD. Volatile solvent components tended to remain in the chamber, and the condensed solvent components acted as a miscible carrier for bitumen components. The analysis further showed that the more efficient oil recovery in SA-SAGD occurred with predominantly cocurrent flow of oil and water near the chamber edge. SA-SAGD recovered a larger amount of asphaltene components (i.e., less in-situ upgrading) than SAGD likely because of its lower chamber temperature, shorter production period, and enhanced local displacement efficiency.

scholarly journals Determination of temperature distribution on windings of oil transformer based on the laws of heat transfer

ScienceRise ◽  
2021 ◽  
pp. 3-13
Author(s):  
Volodymyr Grabko ◽  
Stanislav Tkachenko ◽  
Oleksandr Palaniuk
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Power Transformer ◽  
Experimental Studies ◽  
Short Term ◽  
Transformer Winding ◽  
Transformer Equipment ◽  
Technological Product

Object of research: development of a technology for determining the temperature of the winding of a power oil transformer, in particular, the analysis of thermal processes in the winding of a power transformer during short-term overloads, taking into account the influence of the environment. Investigated problem: temperature distribution in the winding of a power oil transformer taking into account short-term load surges in the problem of assessing the residual life of the insulation of the transformer winding by temperature aging. The calculation of the temperature distribution in the winding was carried out using the passport data and characteristics of the power oil transformer, including the winding, transformer oil, load currents. Main scientific results: a mathematical model was calculated, with the help of which the results of temperature distribution in the transformer winding were obtained during short-term load surges or constant work with an increased load. According to the presented model, the analysis of the cooling time of the transformer winding after short-term overloads is carried out. Comparing the results obtained on the simulation model with the known results of experimental studies of the temperature distribution in the winding of a power transformer, the adequacy of the mathematical model is proved. It is shown that the use of the laws of heat transfer in a homogeneous plate to analyze the temperature distribution in the transformer winding is not wrong, but requires clarifications and simplifications. The area of practical use of the research results: enterprises of the machine-building industry and energy companies specializing in the production and operation of transformer equipment. Innovative technological product: simulation model of heat distribution in a transformer winding, which can take into account the load of the transformer, the effect of the environment on the insulation of the transformer windings. An innovative technological product: a method for diagnosing the duration of the non-failure operation of a transformer, which makes it possible to ensure trouble-free operation and save money for the repair of transformer equipment. Scope of application of the innovative technological product: design and development of diagnostic systems for windings of power oil transformers

Thermal analysis, design, and characterization of a reconfigurable switch matrix based on LTCC technology for satellite communications

2014 ◽  
Vol 2014 (1) ◽  
pp. 000692-000697
Author(s):  
S. Kaleem ◽  
S. Rentsch ◽  
T. Welker ◽  
J. Müller ◽  
M.A. Hein
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Thermal Resistance ◽  
Simulation Model ◽  
Integrated Circuit ◽  
Thermal Characteristics ◽  
Cumulative Effect ◽  
Satellite Communications ◽  
Peak Temperature ◽  
Current Limiting

The thermal characteristics of a reconfigurable switch matrix (RSM) module based on low temperature co-fired ceramic (LTCC) technology are presented. Owing to the PIN-diodes based design, a static power of 1.6 W is dissipated on the ceramic package; the double-sided mounting and integrated bias circuitry demands determination of the temperature distribution within the module. A finite-element thermal simulation model was validated by an infrared (IR) thermograph; the steady-state temperature distribution on the surface of the package estimated by the simulation model differs to the IR measurements by < 1%. This temperature distribution is the result of the thermal interaction among components on the multi-die package with different electrical power dissipation. The temperature on the multi-throw switch monolithic microwave integrated circuit (MMIC) is elevated by ~36.7 K relative to the ambient temperature. The peak temperature occurs on the current-limiting resistors in the bias circuitry; the peak temperature is estimated to be ~45 K above the ambient. In a later version of the RSM, the bias current was reduced by 50%, current-limiting resistor was replaced by two parallel resistors, and additional thermal vias and conductive pads were introduced on the ceramic package. The cumulative effect is a temperature distribution on the package with lowered values. Compared to its predecessor, the temperatures at the current-limiting resistor and the MMIC are reduced by ~20 K and ~14 K, respectively. With one heat source active on the ceramic package at a time, the resulting steady-state temperatures on this source and the remaining heat sources provided an estimate of the self- and transfer-thermal resistances, respectively. The reciprocity of the heat flow on the package and the three-dimensional symmetric layout required only ‘4’ thermal simulations to determine the symmetric thermal resistance matrix. The significantly reduced values of the computed matrix for the later version of the RSM module demonstrated lower thermal resistance to the ambient, compared to its predecessor. Lastly, the results of thermal measurements conducted with a vacuum wafer prober are presented, in order to validate RSM functionality for vacuum pressures (≤ 1 mPa) and temperatures between 248 K and 338 K; the control current and the transmission coefficient demonstrated variations of ≤ 0.5% and −0.015 dB/K, respectively.

Effects of different cooling conditions on friction stir processing of A356 alloy: Numerical modeling and experiment

2021 ◽  
pp. 095440622110456
Author(s):  
Mostafa Akbari ◽  
Parviz Asadi
Keyword(s):  
Wear Resistance ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Material Flow ◽  
A356 Alloy ◽  
Experimental Investigations ◽  
Air Cooling ◽  
The Finite Element Method ◽  
Friction Stir ◽  
Good Agreement

In the present work, the effects of in-process cooling are investigated on the material flow, temperature distribution, axial force, wear resistance, and microstructural and mechanical properties of friction stir processed (FSPed) Al-Si aluminum alloy. The finite element method (FEM) was developed for modeling the process, based on the eulerian-lagrangian technique, and then verified by the experimental force and temperature histories. Next, the material flow and temperature distribution during the friction stir process (FSP) with in-process cooling under different conditions were considered. After that, the experimental investigations, including the optical microscopy, hardness, and wear tests, were conducted. Finally, the stir zone (SZ) shape obtained by experiments and simulation model were compared for the FSPed samples without cooling and with air cooling. The material flow achievements reveal that using a coolant affects the material flow in the pin-driven zone more significantly than in the shoulder-driven zone, leading the SZ to change from the basin shape into the V shape. The SZ shapes obtained from the experiments and the simulation model show a good agreement between the shapes of the samples FSPed without cooling and with air cooling. Moreover, experimental results showed that using in-process cooling reduces Si particles' size and thus significantly increases the hardness and wear resistance. The Si particles size is reduced from 10 μm in the base metal to 2.6 μm and 2 μm in the air-cooled and water-cooled samples. Consequently, the wear mass loss reduced almost 28% and 40%, and hardness increased almost 35% and 80% for the air-cooled and water-cooled samples compared to the processed samples without coolant.

scholarly journals Welding Parameters Optimization in Plunging and Dwelling Phase of FSW Medium Thickness 2219 Aluminum Alloy

2021 ◽  
Author(s):  
Xiaohong Lu ◽  
Jinhui Qiao ◽  
Junyu Qian ◽  
Shixuan Sun ◽  
Steven Y. Liang
Keyword(s):  
Aluminum Alloy ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Rotational Speed ◽  
Parameters Optimization ◽  
Welding Parameters ◽  
Medium Thickness ◽  
Dwelling Time ◽  
Friction Stir ◽  
2219 Aluminum Alloy

Abstract The influence of welding parameters on temperature distribution in plunging and dwelling phase of friction stir welding (FSW) medium thickness 2219 aluminum alloy is blank. Improper selection of welding parameters will result in uneven temperature distribution along the thickness of the weldment, which will lead to welding defects and ultimately affect the mechanical properties of the weldment. To realize the prediction of temperature distribution and achieve the optimization of welding parameters, a simulation model of FSW 18mm thick 2219 aluminum alloy is built based on DEFORM. The validity of the simulation model is verified by temperature measurement experiments. With the minimum temperature difference in the core area of the weldment as target value, and weldable temperature range of 2219 aluminum alloy as constraint conditions, orthogonal experiments are conducted considering the rotational speed, the press amount, the tool tilt angle, the plunging traverse speed and the dwelling time. The results of variance analysis show that the rotational speed and the dwelling time are significant factors affecting temperature field during plunging and dwelling phase. Through single factor simulation, the welding parameters in plunging and dwelling phase are optimized. This study provides a reference for realizing high-quality welding of a heavy rocket fuel tank.

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