Solar Still Heat Transfer Simulation Model

1995 ◽  
Vol 23 (2) ◽  
pp. 113-128
Author(s):  
R. T. Dobson
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Maximum Temperature ◽  
Solar Still ◽  
Daily Production ◽  
Conservation Of Energy ◽  
Introductory Lecture ◽  
Heat Transfer Simulation ◽  
Control Volumes ◽  
Good Agreement

This article serves as a possible basis for the introductory lecture to a first course in heat transfer. By making use of a solar still as a practical example many of the important heat transfer concepts may be interestingly introduced. Conduction, convection and radiation and combinations thereof are all important in the analysis of the performance of a solar still. The conservation of energy and mass is applied to the components of the solar still treated as control volumes. The resulting system of simultaneous differential equations simulating the behaviour of the still are then solved numerically. The results thus obtained are compared to experimental observations. Fairly good agreement between the theoretical and experimental results were obtained, for instance the theoretical daily production of fresh water of 3.15 kg/m2 was 5% less than the experimentally measured value, and the maximum temperature of the water in the still was predicted at 15% more than the experimentally measured value of 62°C.

A heat transfer simulation model for wildfire spread

2006 ◽  
Vol 234 ◽  
pp. S78 ◽  
Author(s):  
Paul Johnston ◽  
George Milne ◽  
Joel Kelso
Keyword(s):  
Heat Transfer ◽  
Simulation Model ◽  
Wildfire Spread ◽  
Heat Transfer Simulation

Numerical and Experimental Model Studies on Thermal Hydraulic Behavior of FBR Internal Core Catcher Assembly

2006 ◽  
Author(s):  
Sanjay Kumar Das ◽  
Anil Kumar Sharma ◽  
A. Jasmin Sudha ◽  
G. Punitha ◽  
G. Lydia ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Maximum Temperature ◽  
Model Studies ◽  
The Core ◽  
Core Catcher ◽  
Internal Core ◽  
Series Of Experiments ◽  
Retention Device ◽  
Good Agreement

Core Catcher is provided as an in-vessel core debris retention device to collect, support, cool and maintain in sub-critical configuration, the generated core debris from fuel melting due to certain postulated Beyond Design Basis Events (BDBE) for Fast Breeder Reactor (FBR). This also acts as a barrier to prevent settling of debris on main vessel and keeps its maximum temperature within acceptable creep range. Heat transfer by natural convection in the core catcher assembly has been assessed numerically and through water experiments using geometrically similar configuration. Resistive heating elements are used in experiment as heat source to simulate debris decay heat on core catcher. Series of experiments were carried out for two configurations referred as geometry A and geometry B. The later configuration showed enhanced natural convective heat transfer from the lower plenum of the vessel. Temperatures were monitored at critical positions and compared with numerical evaluation. Numerically evaluated flow fields and isotherms are compared with experimental data for specific steady state temperatures on heat source plate. Numerical results are found to be in good agreement with that obtained from experiments. The combined efforts of numerical and experimental work conclude core catcher assembly with geometry B to be more suitable.

Characteristics of Heat Transfer During Machining With Rotary Tools

2004 ◽  
Vol 126 (2) ◽  
pp. 404-407 ◽  
Author(s):  
H. A. Kishawy and ◽  
A. G. Gerber
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Rotational Speed ◽  
Measured Temperature ◽  
Tool Rotational Speed ◽  
Radial Temperature ◽  
Conservation Of Energy ◽  
Finite Volume Discretization ◽  
Heat Partitioning ◽  
Good Agreement

In this paper a model is developed to analyze heat transfer and temperature distribution resulting during machining with rotary tools. The presented model is based on a finite-volume discretization approach applied to a general conservation of energy statement for the rotary tool and chip during machining. The tool rotational speed is modeled and its effect on the heat partitioning between the tool and the chip is investigated. The model is also used to examine the influence of tool speed on the radial temperature distribution on the tool rake face. A comparison between the predicted and previously measured temperature data shows good agreement. In general the results show that the tool-chip partitioning is influenced dramatically by increasing the tool rotational speed at low to moderate levels of tool speed. Also, there is an optimum tool rotational speed at which further increase in the tool rotational speed increases the average tool temperature.

Developing an Accurate Heat Transfer Simulation Model of Alaska Pollock Surimi Paste by Estimating the Thermal Diffusivities at Various Moisture and Salt Contents

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Myeong G. Lee ◽  
Jae W. Park ◽  
Won B. Yoon
Keyword(s):  
Heat Transfer ◽  
Thermal Diffusivity ◽  
Moisture Content ◽  
Simulation Model ◽  
Strong Dependence ◽  
Salt Content ◽  
Salt Dependence ◽  
Heat Penetration ◽  
Heat Transfer Simulation ◽  
Thermal Diffusivities

AbstractAlaska pollock (AP) surimi paste was prepared (0–3% salt and 76–84% moisture). The density, specific heat, and thermal conductivity were measured and modelled in temperatures between 25 and 90 °C (R2 > 0.92). The thermal diffusivity (α) function showed a strong dependence on the moisture content and a unique salt dependence at 84% of the moisture content and applied to the heat transfer simulation of surimi paste. The simulation model coupled with the empirical thermal properties accurately predicted the heat penetration curves during heating with RMSE values ranging from 0.43 to 1.22 °C. The salt dependence on thermal diffusivity was identified and modeled only at 84% moisture content. With a model for 84% moisture content, the RMSE value of 3% salt content decreased from 1.11 °C to 0.56 °C. This study demonstrated that an accurate prediction of the heat transfer of the surimi paste needs to be coupled with the nonlinear thermal diffusivity functions.

Simulation Model for Calculating Pavement Temperatures Including Maximum Temperature

2000 ◽  
Vol 1699 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Åke Hermansson
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Simulation Model ◽  
Wind Velocity ◽  
Air Temperature ◽  
Input Data ◽  
Finite Difference Approximation ◽  
Maximum Temperature ◽  
Difference Approximation ◽  
Pavement Surface

A simulation model has been developed to calculate the temperatures of asphalt concrete during summer. Input data to the simulation model are hourly values for solar radiation, air temperature, and wind velocity. Longwave radiation incident to and outgoing from the pavement surface is calculated from the air and pavement surface temperatures, respectively. The portion of the incident shortwave radiation absorbed by the pavement surface is calculated from the albedo of the surface. By means of a finite difference approximation of the heat transfer equation, the temperatures are calculated under the surface. Apart from radiation and heat transfer, convection losses from the pavement surface are also calculated depending on wind velocity, air temperature, and surface temperature. The formulas used for the calculation of radiation and the simulation model as a whole are validated by comparison with measurements, showing good agreement. A method for the calculation of direct solar radiation from a clear sky, at an arbitrary location and time, is used to create input data to the simulation model in order to calculate maximum pavement temperatures. The formulas used with Superpave to calculate maximum pavement temperatures are based on the assumption that there is an equilibrium when a maximum temperature is reached. Such an equilibrium assumption can be strongly questioned, and its consequences are discussed.

Flow Fields Investigation and Temperature Distribution on a Rotating Disk Imposed by a Turbulent Impinging Jet

2010 ◽  
Author(s):  
H. Karrabi ◽  
S. Rasoulipour
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Convection Heat Transfer ◽  
Rotating Disk ◽  
Maximum Temperature ◽  
Cooling Process ◽  
Maximum Temperature Difference ◽  
Average Temperature ◽  
Disk Material ◽  
Good Agreement

Numerical investigation of fluid flow structure and convective heat transfer due to a circular jet impinging on a rotating disk is performed. Temperature and convection heat transfer coefficient are calculated. Flow is considered to be steady, incompressible and turbulent. k-ε RNG model is used to model the turbulent flow. Results are compared with experimental data showing good agreement. Two new criteria are introduced and used to evaluate the performance of cooling process, the first is maximum temperature difference on the disk, and the second is the average temperature of the disk. The first parameter shows the uniformity of temperature distribution in the disk and the second shows the effect of both thermo physical properties of the disk material and cooling process.

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