Natural Ventilation in a Model Room

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Sudhakar Subudhi ◽  
K. R. Sreenivas ◽  
Jaywant H. Arakeri
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Natural Ventilation ◽  
Constant Heat Flux ◽  
Bottom Plate ◽  
Bottom Surface ◽  
Buoyant Jet ◽  
Buoyant Jets ◽  
Fluid Medium ◽  
Model Room

Natural ventilation of a model room with water as the fluid medium is studied. It is insulated by air gaps on the four sides and at the top. A constant heat flux has been maintained on the bottom surface of the room. This room is surrounded by a large exterior tank containing water. There are three openings each on two opposing sides of the model room. For any experiment, only one opening on each side is kept open. Fluid enters or leaves these openings and the flow is driven entirely by buoyancy forces. Shadowgraph technique is used for visualization. The buoyancy causes flow to enter through the bottom opening and leaves through the top opening. At the openings, buoyant jets are observed and which have higher or lower relative density compared with that of its environment. The buoyant jet at the inlet interacts with the plumes on the heated bottom plate. From these visualizations, it appears that free convection at bottom plate will be affected by the buoyant jets at the openings and the degree to which it is affected depends on the position and size of openings and distance between inlet and outlet. The flow rate due to the natural ventilation depends on the bottom surface heat flux and the height difference between the openings. The temperatures of the floor, the interior and the exterior are calculated using a simple mathematical model. The values of temperatures obtained in the experiments are reasonably well predicted by the mathematical model.

Study of buoyant jets in natural ventilation of a model room

2013 ◽  
Vol 64 ◽  
pp. 91-97 ◽  
Author(s):  
Sudhakar Subudhi ◽  
K.R. Sreenivas ◽  
Jaywant H. Arakeri
Keyword(s):  
Natural Ventilation ◽  
Buoyant Jets ◽  
Model Room

Mixed Convection Heat Transfer With Longitudinal Fins in a Horizontal Parallel Plate Channel: Part I—Numerical Results

1990 ◽  
Vol 112 (3) ◽  
pp. 612-618 ◽  
Author(s):  
J. R. Maughan ◽  
F. P. Incropera
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mixed Convection ◽  
Secondary Flow ◽  
Heated Surface ◽  
Bottom Plate ◽  
Bottom Surface ◽  
Uniform Heat Flux ◽  
Uniform Heat ◽  
Fin Spacing

Numerical calculations for laminar, fully developed mixed convection in a longitudinally finned horizontal channel have been performed for two sets of boundary conditions: (i) an isothermal, heated bottom plate with an isothermal, cooled top plate, and (ii) a uniform heat flux at the bottom surface with an adiabatic upper surface. Heat transfer and the strength of the buoyancy-driven secondary flow increase with increasing Rayleigh number and fin height. Fin spacing affects heat transfer through changes in the axial velocity distribution, the strength of the secondary flow, and the heated surface area, with decreased spacing acting to inhibit secondary flow. For the uniform heat flux condition and a small available pressure drop, close fin spacing can significantly reduce the channel flow rate and increase maximum plate temperatures.

Rate of Sublimation of Ice by Radiative Heating in Freeze-Etching

1980 ◽  
Vol 38 ◽  
pp. 618-619
Author(s):  
Yeshayahu Talmon
Keyword(s):  
Heat Flux ◽  
Freeze Fracture ◽  
Constant Heat Flux ◽  
Radiative Heating ◽  
Constant Heat ◽  
Entire Sample ◽  
Simplified Method ◽  
Freeze Etching ◽  
Sublimation Rates ◽  
Fractured Surface

To bring out details in the fractured surface of a frozen sample in the freeze fracture/freeze-etch technique,the sample or part of it is warmed to enhance water sublimation.One way to do this is to raise the temperature of the entire sample to about -100°C to -90°C. In this case sublimation rates can be calculated by using plots such as Fig.1 (Talmon and Thomas),or by simplified formulae such as that given by Menold and Liittge. To achieve higher rates of sublimation without heating the entire sample a radiative heater can be used (Echlin et al.). In the present paper a simplified method for the calculation of the rates of sublimation under a constant heat flux F [W/m2] at the surface of the sample from a heater placed directly above the sample is described.

scholarly journals The exact analytical solution of the dual-phase-lag two-temperature bioheat transfer of a skin tissue subjected to constant heat flux

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hamdy M. Youssef ◽  
Najat A. Alghamdi
Keyword(s):  
Heat Flux ◽  
Analytical Solution ◽  
Exact Analytical Solution ◽  
Constant Heat Flux ◽  
Bioheat Transfer ◽  
Skin Tissue ◽  
Phase Lag ◽  
Dual Phase ◽  
Constant Heat ◽  
Two Temperature

Abstract This work is dealing with the temperature reaction and response of skin tissue due to constant surface heat flux. The exact analytical solution has been obtained for the two-temperature dual-phase-lag (TTDPL) of bioheat transfer. We assumed that the skin tissue is subjected to a constant heat flux on the bounding plane of the skin surface. The separation of variables for the governing equations as a finite domain is employed. The transition temperature responses have been obtained and discussed. The results represent that the dual-phase-lag time parameter, heat flux value, and two-temperature parameter have significant effects on the dynamical and conductive temperature increment of the skin tissue. The Two-temperature dual-phase-lag (TTDPL) bioheat transfer model is a successful model to describe the behavior of the thermal wave through the skin tissue.

Sign in / Sign up

Export Citation Format

Share Document