PRESSURE OSCILLATIONS IN FORCED CONVECTION HEATING OF GASES

Author(s):  
V. S. Krishnan ◽  
John C. Friedly
1964 ◽  
Vol 86 (1) ◽  
pp. 39-48 ◽  
Author(s):  
E. Smithberg ◽  
F. Landis

Velocity distributions, friction losses, and heat-transfer characteristics were studied analytically and experimentally for fully developed turbulent flow in tubes with twisted tape swirl generators. Data were obtained for pitch-to-diameter ratios from 3.62 to 22.0 with both air and water under isothermal and forced convection heating conditions. The following principal conclusions result: (a) The velocity field is helicoidal and corresponds to a forced vortex in the core superposed on an essentially uniform axial flow. (b) Friction losses may be predicted from the combined effects of the axial and tangential boundary-layer flows coupled with an additional “vortex-mixing” effect. (c) Approximate heat-transfer correlations can be predicted from a Colburn-type analysis. These may be improved by considering a boundary layer and vortex mixing model.


2006 ◽  
Vol 11 (4) ◽  
pp. 331-343 ◽  
Author(s):  
M. S. Alam ◽  
M. M. Rahman ◽  
M. A. Samad

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.


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