Research on the Mathematical Model of the Plastic Profile Cooling Analysis

2012 ◽  
Vol 164 ◽  
pp. 214-217
Author(s):  
Xiang Shan Huang ◽  
Li Dan Chen
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Thermal Analysis ◽  
Reynolds Number ◽  
Theoretical Basis ◽  
Flow State ◽  
Function Blocks ◽  
Plastic Profile ◽  
The Mathematical Model ◽  
Fluid Parameters

According to the assumption of the plastic profile cooling analysis, Prandtl number Pr and Reynolds number Re can be derived from the fluid parameters. The paper judge and analyze the movement of flow state, further study the formula of heat transfer coefficient α, thermal analysis and boundary conditions in Reynolds number Re. The experimental results show mathematical model, which provides a theoretical basis for the cooling and forming of function blocks, it has certain guiding significance.

Finite Element Thermal Analysis on Heat Transfer Performance of Rectangular Micro – Groove Flat Heat Pipe

2013 ◽  
Vol 721 ◽  
pp. 456-460
Author(s):  
Yi Bing Liu
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Thermal Analysis ◽  
Heat Pipe ◽  
Heat Transfer Process ◽  
Pipe Surface ◽  
Iterative Computation ◽  
Flow And Heat Transfer ◽  
The Mathematical Model ◽  
Flat Heat Pipe

Having fully considered the influence of gas-liquid interfacial friction on the heat transfer characteristics of heat pipe within the channel, the mathematical model of the flow and heat transfer process in the Rectangular Micro-groove flat heat pipe is established. The simulation is performed by using thermal analysis software ANSYS. The iterative computation values of the center point temperature of the heat pipe surface being compared with the simulation results, the error is only 5.27% and the two are basically the same values, which shows that the mathematical model has a guiding significance on the analysis of heat pipe theory.

Systems Actuated by Shape Memory Alloys: Identification and Modeling

2021 ◽  
Vol 1 (2) ◽  
pp. 12-20
Author(s):  
Najmeh Keshtkar ◽  
Johannes Mersch ◽  
Konrad Katzer ◽  
Felix Lohse ◽  
Lars Natkowski ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Numerical Simulations ◽  
Shape Memory ◽  
Transfer Equation ◽  
Mechanical Parameters ◽  
Heat Transfer Equation ◽  
The Mathematical Model

This paper presents the identification of thermal and mechanical parameters of shape memory alloys by using the heat transfer equation and a constitutive model. The identified parameters are then used to describe the mathematical model of a fiber-elastomer composite embedded with shape memory alloys. To verify the validity of the obtained equations, numerical simulations of the SMA temperature and composite bending are carried out and compared with the experimental results.

scholarly journals Development of condenser mathematical model for research and development of ways to improve its efficiency

2020 ◽  
Vol 18 (4) ◽  
pp. 578-585
Author(s):  
Madina Shavdinova ◽  
Konstantin Aronson ◽  
Nina Borissova
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Water Temperature ◽  
Steam Turbine ◽  
Cooling Water ◽  
Laboratory Research ◽  
Thermal Engineering ◽  
Linear Regression Method ◽  
Cooling Water Temperature ◽  
The Mathematical Model

The condensing unit is one of the most important elements of the steam turbine of a combined heat and power plant. Defects in elements of the condensing unit lead to disturbances in the steam turbine operation, its failures and breakdowns, as well as efficiency losses of the plant. Therefore, the operating personnel need to know the cause of the malfunction and to correct it immediately. There are no diagnostic models of condensers in the Republic of Kazakhstan at the moment. In this regard, a mathematical model of a condenser based on the methodology of Kaluga Turbine Plant (KTP) has been developed. The mathematical model makes it possible to change the input parameters, plot dependency diagrams, and calculate the plant efficiency indicators. The mathematical model of the condenser can be used to research ways for the improvement of the condensing unit efficiency, for diagnostic purposes of the equipment condition, for the energy audit conduction of the plant, and in the training when performing virtual laboratory research. Using static data processing by linear regression method we obtain that the KTP methodology of condenser calculation is fair at cooling water temperature from 20 °C to 24 °C, but at cooling water temperature from 20 °C to 28 °C, the methodology of JSC "All-Russia Thermal Engineering Institute" (JSC "VTI") is used. One of the ways to increase the condenser efficiency has been proposed. It is the heat transfer augmentation with riffling annular grooves on tubes. This method increases the heat transfer coefficient by 2%, reduces the water subcooling of the heating steam by 0.9 °C, and decreases the cooling area by 2%.

scholarly journals Study on the Mathematical Model of Vacuum Breaker Valve for Large Air Mass Conditions

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1358
Author(s):  
Zhang ◽  
Fan ◽  
Yu ◽  
Zhang ◽  
Lv ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Theoretical Basis ◽  
Isothermal Process ◽  
Air Mass ◽  
Protection Scheme ◽  
Calculation Results ◽  
Air Valve ◽  
The Mathematical Model ◽  
Valve Model ◽  
Derivation Process

The mathematical model of vacuum breaker valve is significant to the protection scheme. The more accurate the vacuum breaker valve model, the more reliable the calculation results. In this study, the application conditions of the air valve model are analyzed according to the assumptions used in the derivation, and the contradictions between these assumptions are proposed. Then, according to the different working characteristics between the vacuum breaker valve on the siphon outlet pipe and the air valve, the vacuum breaker valve model is deduced based on the modified assumptions. In the derivation process, the thermodynamic change of the gas in the vacuum breaker valve is assumed to follow the isentropic process rather than an isothermal process, and the water level in the vacuum breaker valve is considered to be changeable. An engineering case is introduced, and the results calculated according to the vacuum breaker valve model are compared with those resulting from the air valve model. The results indicate that the vacuum breaker valve model is suitable for large air mass conditions and can provide a theoretical basis for the numerical simulation and settings of vacuum breaker valves.

Parametric Study of Temperature Field During the Cooling Stage for Extrusion Blow Molded Part

2005 ◽  
Author(s):  
Zhan-Song Yin ◽  
Hon-Xiong Huang
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Internal Heat ◽  
Mold Material ◽  
Orthogonal Experimental Design ◽  
Ann Model ◽  
Molded Part ◽  
Artificial Neural Network Ann ◽  
The Mathematical Model ◽  
Part Thickness

A mathematical model of the transient heat transfer during the cooling and solidification of extrusion blow molded part was developed. The temperature profiles were obtained by using finite element (FE) code POLYFLOW to solve the mathematical model. The influences of blow mold material, internal heat transfer coefficient, part thickness, and initial parison temperature on cooling were analyzed. An orthogonal experimental design was applied to determine the significance of four process parameters on the time for opening the mold. The calculated results were estimated by analysis of variance (ANVOA). An artificial neural network (ANN) model based on the numerical simulation data was developed to build for predicting the temperature distribution across thickness. The results showed that ANN approach was an effective method for analyzing the cooling of blow molded part.

scholarly journals Mixed Convection Magnetohydrodynamics Flow of a Nanofluid with Heat Transfer: A Numerical Study

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Abdul Quayam Khan ◽  
Amer Rasheed
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Time Derivative ◽  
Moving Plate ◽  
Finite Difference Discretization ◽  
The Mathematical Model ◽  
Fluid Parameters

In this paper we have studied the magnetohydrodynamic (MHD) mixed convection Maxwell flow of an incompressible nanofluid with magnetic field and heat transfer over a moving plate aligned horizontally. Thermal radiation has also been applied in order to investigate its effects on velocity and temperature variations in the fluid. The Caputo time derivative has been employed to derive the mathematical model. A numerical solution has been obtained using finite difference discretization along with L1-algorithm. Fractional and other pertinent physical fluid parameters like magnetic field parameter, thermal radiation, effect on velocity, and temperature distribution are analyzed and demonstrated through graphs.

Heat Convection from a Horizontal Cylinder Rotating in a Quiescent Fluid

1986 ◽  
Vol 10 (3) ◽  
pp. 141-152
Author(s):  
H.M. Badr ◽  
S.M. Ahmed
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Horizontal Cylinder ◽  
Heat Transfer Process ◽  
Two Dimensional ◽  
Two Dimensional Flow ◽  
Boussinesq Fluid ◽  
The Mathematical Model ◽  
Quiescent Fluid

The aim of this work is a theoretical investigation to the problem of heat transfer from an isothermal horizontal cylinder rotating in a quiescent fluid. The study is based on the solution of the conservation equations of mass, momentum and energy for two-dimensional flow of a Boussinesq fluid. The effects of the parameters which influence the heat transfer process namely the Reynolds number and Grashof number are considered while the Prandtl number is held constant. Streamline and isotherm patterns are obtained from the mathematical model and the results are compared with previous experimental data. A satisfactory agreement was found.

Study on Heat Transfer and Flow Behavior of Mini-Tube Bank for Micro Heat Exchanger

2006 ◽  
Author(s):  
Y. Koizumi ◽  
T. Okuyama ◽  
H. Ohtake
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Behavior ◽  
Flow State ◽  
Wake Region ◽  
Tube Bank ◽  
Disturbed Condition ◽  
The Heat Transfer Coefficient

Heat transfer and flow behavior in the mini tube bank were examined. The tube bank was composed of 1 mm diameter nickel wires and a 30 mm wide × 15 mm high flow channel. Experiments were performed in the range of the rod Re = 5 ~ 430 by using water. Numerical analyses were also conducted with the commercial CFD code STAR-CD. The heat transfer coefficient after the second row was lower than first row's one. The flow visualization results indicated that the wake region was stagnant when the Reynolds number was low. This flow stagnation seemed to cause the heat transfer coefficient deterioration in the tube bank. As the Reynolds number was increased, the flow state in the wake region gradually changed from the stagnant condition to the more disturbed condition. The deeper the row was, the more disturbed the wake was. The heat transfer coefficient began to recover to the first row value at certain Reynolds number. The recovery started from the most downstream row; fifth row in the present experiments and was propagated to the upstream row. The Reynolds number when the recovery was initiated decreased as the spacing between rods was increased. The analytical results of the STAR-CD code supported the experimental results. When the wake was stagnant, the heat transfer coefficient distribution around the rear rod, i.e. the rod in the wake, showed a large dip in the front region of the rod. It was considered that this dip caused the heat transfer coefficient decrease after the second row observed in the experiments.

Experimental Research on Performance of Heat Transfer and Pressure Drop for Primary Surface Recuperator With Mini Channels

2011 ◽  
Author(s):  
Hugen Ma ◽  
Hui Gao ◽  
Wenjing Tu
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Pressure Drop ◽  
Experimental Research ◽  
Transfer Factor ◽  
Flow And Heat Transfer ◽  
Good Consistency ◽  
Mini Channels ◽  
Performance Of Heat Transfer ◽  
The Mathematical Model

Based on the single blow technique, experimental research was conducted for the performance of heat transfer and flow drop for six test cores with cross corrugated (CC) or corrugated undulated (CU) primary surfaces for different geometries. After the mathematical model was established for heat transfer under the condition of single blow, a matching numerical solution was obtained for different NTU. The correlations of hear transfer factor j and friction factor f were obtained for three types of cross corrugated primary surfaces (crossed angle 45∼75°) with a range of Re = 120∼800 and three types of corrugated undulated primary surfaces (crossed angle 52.5∼67.5°) with a range of Re = 200∼1200. Hydraulic diameters of all heat transfer surfaces are from 1.2∼1.48mm. Analysis on the flow and heat transfer for cross corrugated and corrugated undulated primary surfaces was made based on the comprehensive evaluating factor j/f. The experimental results were compared to references with good consistency. The regressive errors of correlations were less than 16%.

Studi Perpindahan Panas Material pada Sistem Koordinat Segitiga

2017 ◽  
Vol 1 ◽  
pp. 114
Author(s):  
Imam Basuki ◽  
C Cari ◽  
A Suparmi
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Partial Differential Equations ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Numerical Solution ◽  
Difference Method ◽  
The Finite Difference Method ◽  
The Mathematical Model

<p class="Normal1"><strong><em>Abstract: </em></strong><em>Partial Differential Equations (PDP) Laplace equation can be applied to the heat conduction. Heat conduction is a process that if two materials or two-part temperature material is contacted with another it will pass heat transfer. Conduction of heat in a triangle shaped object has a mathematical model in Cartesian coordinates. However, to facilitate the calculation, the mathematical model of heat conduction is transformed into the coordinates of the triangle. PDP numerical solution of Laplace solved using the finite difference method. Simulations performed on a triangle with some angle values α and β</em></p><p class="Normal1"><strong><em> </em></strong></p><p class="Normal1"><strong><em>Keywords:</em></strong><em>  heat transfer, triangle coordinates system.</em></p><p class="Normal1"><em> </em></p><p class="Normal1"><strong>Abstrak</strong> Persamaan Diferensial Parsial (PDP) Laplace  dapat diaplikasikan pada persamaan konduksi panas. Konduksi panas adalah suatu proses yang jika dua materi atau dua bagian materi temperaturnya disentuhkan dengan yang lainnya maka akan terjadilah perpindahan panas. Konduksi panas pada benda berbentuk segitiga mempunyai model matematika dalam koordinat cartesius. Namun untuk memudahkan perhitungan, model matematika konduksi panas tersebut ditransformasikan ke dalam koordinat segitiga. Penyelesaian numerik dari PDP Laplace diselesaikan menggunakan metode beda hingga. Simulasi dilakukan pada segitiga dengan beberapa nilai sudut  dan  </p><p class="Normal1"><strong> </strong></p><p class="Normal1"><strong>Kata kunci :</strong> perpindahan panas, sistem koordinat segitiga.</p>

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