Prediction of Temperature Distribution in a Food Self-Heating System

2010 ◽  
Author(s):  
Son H. Ho ◽  
Muhammad M. Rahman ◽  
Aydin K. Sunol
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Thermal Performance ◽  
Exothermic Reaction ◽  
Heating System ◽  
Food Tray ◽  
Governing Equations ◽  
Heating Unit ◽  
Self Heating ◽  
Heating Profiles

This paper presents a numerical modeling and simulation of heat transfer in a food self-heating unit for group meals. A model of a water-activated heater based on an exothermic reaction was developed. The resulting governing equations of heat conduction and chemical reaction were solved for an analytical approximate solution, to which experimental data found from literature were compared and curve fitted. Then a model of a complete food-heating unit, which includes a stack of four sets of food tray, heating tray, and heater sandwiched between them, as well as the cardboard container, was developed. A system of governing equations for heat transfer in the composite medium for the complete model was solved. Numerical solution of temperature distribution within the food-heating unit is presented. The responses in thermal performance of the heating system to the parameters that influence heating profiles of the heater such as decay constant and heat generation were studied in order to improve the thermal performance of the heating system. The results are useful for designing and optimizing self-heating systems for food served to groups of many people.

scholarly journals Mathematics Modelling and Performance Analysis of the Heat Transfer on Vacuum Tube Collector of Water Heater Application

2020 ◽  
Vol 190 ◽  
pp. 00022
Author(s):  
Lia Hamanda ◽  
Gunawan Nugroho
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Thermal Performance ◽  
Solar Collector ◽  
Dynamic Behaviour ◽  
Tube Axis ◽  
Outdoor Temperature ◽  
Water Heater ◽  
And Performance ◽  
Mathematical Modelling And Simulation

The aim of this work is to study a mathematical modelling and simulation for predicting the thermal performance heat-pipe evacuated a solar collector for water heater, which was considered the temperature distribution along the tube axis and radius. This model used to help in studying the dynamic behaviour of the system design and the effect of influential parameter on the water heater process. The result showed that water heating is affected by the surface of collector, metrological conditions such as solar radiation and outdoor temperature, even the thermal performance of the collector.

Heat Transfer Enhancement in Corrugated Pipes

2010 ◽  
Author(s):  
Dennis A. Siginer ◽  
F. Talay Akyildiz
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Heat Transfer Enhancement ◽  
Temperature Fields ◽  
Governing Equations ◽  
Transfer Enhancement ◽  
Exact Analytical Solutions ◽  
Velocity And Temperature Fields ◽  
Steady Laminar

The temperature distribution and heat transfer coefficient are investigated in forced convection with Newtonian fluids in pressure gradient driven hydrodynamically and thermally fully developed steady laminar flow in transversally corrugated pipes. The governing equations are solved by means of the epitrochoid conformal mapping and exact analytical solutions are derived for the velocity and temperature fields without viscous dissipation. The effect of the corrugations and the number of waves on the friction factor, the temperature distribution and the heat transfer enhancement is discussed.

Modeling the Effects of Heat Transfer Processes on Material Strain and Tension in Roll to Roll Manufacturing

2013 ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Distribution Model ◽  
Tension Zone ◽  
Governing Equations ◽  
Flexible Materials ◽  
Transfer Processes ◽  
Roll To Roll ◽  
Average Modulus ◽  
The Web

This paper develops governing equations for material strain and tension based on a temperature distribution model when the flexible materials (often called webs) are transported on rollers through heat transfer processes within roll-to-roll (R2R) processing machines. Heat transfer processes are employed widely in R2R systems that contain process operations such as printing, coating, lamination, etc., which require heating/cooling of the moving web material. The heat transfer processes introduce the thermal expansion/contraction of the material and changes in the elastic modulus. Thus, the temperature distribution in the moving material affects the strain distribution in the material. Because of change in strain as well as modulus as a function of temperature, tension in the material resulting from elastic strain is also affected by heating/cooling of the web. To obtain the temperature distribution, two basic heat transfer modes are considered: web wrapped on a heat transfer roller and the web span between two consecutive rollers. The governing equations for strain is then obtained using the law of conservation of mass considering the temperature effects. Subsequently, a governing equation for web tension is obtained by assuming the web is elastic with the modulus varying with temperature; an average modulus is considered for defining the constitutive relation between web strain and tension. Since it is difficult to obtain measurement of tension using load cell rollers within heat transfer processes, a tension observer is designed. To evaluate the developed governing equations, numerical simulations for a single tension zone consisting of a heat transfer roller, a web span, and a driven roller are conducted. Results from these numerical model simulations are presented and discussed.

Efficiency Comparison Between Circular and Semicircular Fins Circumscribing Circular Pipes

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
R. Chakraborty ◽  
A. Sirkar
Keyword(s):  
Temperature Distribution ◽  
Thermal Performance ◽  
Numerical Results ◽  
Circular Pipe ◽  
Two Dimensional ◽  
Governing Equations ◽  
Degree Polynomial ◽  
Circular Pipes ◽  
Efficiency Comparison ◽  
Detailed Derivation

A new design of fin has been conceived, which is in the shape of a semicircular strip. A step-by-step straightforward detailed derivation of the governing equations for two-dimensional temperature distribution in a semicircular fin has been presented, assuming a third degree polynomial. Numerical results are presented to illustrate the effects of pipe size and the number of semicircular fins on the thermal performance of the fin. It has been shown mathematically that the efficiency of a semicircular fin can be greater than that of a circular fin, having same total volume of fin material when employed over the circumference of a circular pipe.

scholarly journals Heat Transfer Analysis and Performance Measurements of Hollow Pin-fin in Natural Convection

2019 ◽  
Vol 8 (6S) ◽  
pp. 727-731
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Temperature Distribution ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Thermal Performance ◽  
Temperature Drop ◽  
Heat Transfer Analysis ◽  
Pin Fin ◽  
And Performance

The Fin act as dissipiating elements, selection of proper geometry plays crusial role in increasing the rate of heat transfer and performance of the system. This work has been undertaken to investigate and compare thermal performance of solid and hollow pin-fin. Heat transfer analysis of solid and hollow pin fin carried and the results was compared with the experimental results. experiment was conducted to analyze the natural convection around solid hollow pin fin, and compare thermal performance of hollow pin fin with the solid pin fin of same dimension and orientation. The experimental result of temperature distribution shows that the faster temperature drop along the length. The high value of convective heat transfer in the initial phase due to which faster temperature drop takes place. Convection is found to be dominating due to less area for conduction along the length. Theoretical value and experimental value are close to each for temperature distribution as well the convective heat transfer coefficient. Efficiency is reduced in the case of hollow fin but the effectiveness of the hollow pin fin is increased by 1.76 times from an economical point of view, holoow pin fin is more efficient solution.

Simulation Analysis of Heat Transfer on Low Temperature Hot-Water Radiant Floor Heating and Electrical Radiant Floor Heating

2012 ◽  
Vol 204-208 ◽  
pp. 4234-4238
Author(s):  
Han Bing Qi ◽  
Fu Yun He ◽  
Qiu Shi Wang ◽  
Dong Li ◽  
Lin Lin
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Low Temperature ◽  
Heating System ◽  
Heat Transfer Process ◽  
Hot Water ◽  
Radiant Heating ◽  
Radiant Floor Heating ◽  
Heating Mode ◽  
Floor Heating

Radiant floor heating as a new type of energy-saving heating method has more and more used in modern building heating project. According to the different heat source, radiant floor heating is divided into low temperature hot-water floor radiant heating and electrical floor radiant heating. This paper analyzes the heat transfer process of structure layer of the low temperature hot-water and electrical floor radiant heating system, establishes two dimensional steady heat transfer mathematic model, numerical calculation using Fluent software. Respectively simulated when floor materials is different, the heat transfer process of low temperature hot-water floor radiant heating and electrical floor radiant heating system, The analysis results show that: for low temperature hot-water floor radiant heating, when floor material is soft wood, the ground temperature distribution is more uniform; for electrical floor radiant heating, when floor materials is marble, the ground temperature distribution is more uniform; electrical floor radiant heating is more energy saving, and temperature distribution in the ground of floor using the constant heat flux electric heating mode is more uniform than which using the low temperature hot water heating mode.

Numerical Analysis of Temperature Distribution in Generator Stator Bar with Different Insulation Thermal Performance

2014 ◽  
Vol 529 ◽  
pp. 655-659
Author(s):  
Li Zhang ◽  
Yi Ming Lei
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Numerical Analysis ◽  
Thermal Performance ◽  
Good For ◽  
Generator Stator

Accurate descripting the temperature distribution of stator bars for the genaraors with big capacity is necessary. The stator bar of one 600MW generator was simulated for getting the temperature distribution. Several methods of dealing with the insulations were compared. How the heat conduction performance of insulations is good for the heat transfer of stator bars was discussed.

scholarly journals Study on the Thermal Performance and Temperature Distribution of Ball Bearings in the Traction Motor of a High-Speed EMU

2020 ◽  
Vol 10 (12) ◽  
pp. 4373
Author(s):  
Yu Wang ◽  
Junci Cao ◽  
Qingbin Tong ◽  
Guoping An ◽  
Ruifang Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Thermal Performance ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Ball Bearings ◽  
Convection Heat ◽  
Rolling Bearings ◽  
Traction Motors

The transient thermal performance of rolling bearings affects the mechanical performance and system safety of traction motors. Most of the traditional empirical formulas used in temperature analysis have been simplified and cannot be completely applied to the calculation of heat generation and convection heat transfer coefficients. Based on the comparative analysis of finite element transient temperature and experimental data, this paper proposes a correction method of mathematical model and derives an accurate calculation formula for the heat generation and lubricant convection heat transfer coefficient of ball bearings applicable for the non-driving end in the traction motor of a high-speed EMU (Electric Multiple Unit). The accuracy of the results has been verified by durability experiment data. In addition, with changes in speed, radial load and other factors taken into account, we have analyzed the influence of these time-varying factors on ball bearing temperature, as well as the temperature distribution law of each component in a grease-lubricated bearing, in a bid to lay a foundation for follow-up research on the heat transfer laws of traction motors and rolling bearings.

scholarly journals AN EXPERIMENTAL VERIFICATION OF INFLUENCING FACTORS ON THE MECHANISM OF HEAT TRANSFER IN THE CAVITY ROOF VENTILATION

2015 ◽  
Vol 5 (2) ◽  
Author(s):  
DRAGANA TEMELJKOVSKI
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Thermal Performance ◽  
Experimental Verification ◽  
Thermal Damage ◽  
Building Envelope ◽  
Cooling Effect ◽  
The Sun ◽  
Key Words Temperature

The roof, as a part of the building envelope with the thermal performance that’s a major requirement for guaranteeing a comfortable and hygienic interior climate, provides protection from thermal damage incurred by the sun. To improve this protection ability, the use of a ventilated roof can be considered, which has a ventilation layer known as a cavity, beneath the roof cover panel. Based on the proposed mechanism of heat transfer and the influence of such factors as cavity ventilation, the slope of the roof, intensity of solar radiation, the size and shape of the cavity, and panel profiles, airflow and temperature distribution are analyzed in the cavity, in an effort to improve the cooling effect of ventilation in the cavity of the roof. In this study, the influence of these elements on airflow is studied. Key words: temperature distribution, cooling effect, air flow, thermal comfort, ventilation channel.

Sign in / Sign up

Export Citation Format

Share Document