Flow and Heat Transfer around Rectangular Prism

Research Project

Project/Area Number	60550113
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Fluid engineering
Research Institution	Kitami Institute of Technology
Principal Investigator	SAKAMOTO Hiroshi Kitami Institute of Technology , Faculty of Engineering ,Professor, 工学部, 教授 (70003176)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywords	Prism Model / Turbulent Boundary Layer / Flow Pattern / Surface Pressure Distribution / Vortex Shedding / Two Prisms / Separated and Reattached / Flow / Averaged Heat Transfer
Research Abstract	The fluid flow and heat transfer around rectangular prism placed vertically in a turbulent boundary layer were investigated experimentally. Experimental data were collected to investigate the effects of (1) the height/width ratio of the prism with a square cross section, (2) the angle of incidence of the approaching flow with respect to the prism. The primary results of those investigations will be summarized as follows: (1) On the basis of the measurement of the flow pattern over the floor on which the prism was placed using an oil-film visualization, the separated region governing the heat transfer around the prism model is proved. (2) From the measurement of the surface pressure of the prism model, it is clear that the positions of reattachment, where the heat transfer reaches a maximum value, vary remarkably with change in angle of incidence. (3) By measuring the smoke pattern in the wake governing the heat transfer toward downstream, it is clear that two types of vortex are formed behind it; they are the arch-type vortex and the Karman-type vortex. Further, these vortices starts to dissipate in the very vicinity downstream of the prism before convectim far downstream. (4) The flow pattern for two closely placed prisms are fairly different from those for a single prism, owing to the interaction effect between the two prisms. Accordingly further work is necessary for the heat transfer around the two prisms. (5) The local and averaged heat transfer around the prism become clear in connection with the flow characteristics. Especially, it is clear that the heat transfer shows the maximum value at the position where the separated shear layer reattaches on the surface of the prism.