Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

BOUNDARY LAYER CONTROL BY HEAT TRANSFER STRIPS: AN ASYMPTOTIC APPROACH

Get access (open in a dialog) DOI: 10.1615/IHTC11.1940
pages 345-350

Abstrakt

The effect of heating strips on the stability of boundary layer flow over a flat plate is investigated. The heating strip alters the flow stability through the temperature dependence of the fluid properties. An asymptotic expansion for the fluid properties in terms of the total heat input is used. Parallel and non-parallel linear stability studies are carried out that calculate the effects of temperature dependent fluid properties in terms of asymptotic expansions. The leading order influence is obtained as a general result and, for the particular Prandtl number taken, is independent of any particular set of property laws. In a fluid in which the intrinsic viscosity increases with temperature and the density decreases with temperature (such as air) the results of parallel flow theory show that the optimal location for a heating strip to stabilise the flow is upstream of the neutral point. The optimal location moves further upstream as the total heat input level is increased. For a given heat input widening the heating strip further stabilises the flow. The results using the non-parallel flow analysis indicate that these effects may be large in the regions close to the strip edges. The potential of the asymptotic method as a tool for further analysis of the flow is discussed.