Heat transfer to the transpired turbulent boundary layer

Abstract

This paper contains a summarization of five years work on an investigation on heat transfer to the transpired turbulent boundary layer, The experimental results are presented for friction coefficient and Stanton number over a wide range of blowing and suction for the case of constant free-stream velocFty, 5olding ccnstarrt certain blowing parameters. The problem of the accelerated turbulent boundary layer with transpiration is considered, experimental data are presented and discussed, and theoretical models for solution of the momentum equation under these conditions are presented. Data on teirbulenr Prandtl number are presented so that solutions to the energy equation may be obtained. Some examples of boundary layer heat transfer and friction coefficient are presented using one of the models discussed, employing a finite difference solution method. iii mass t r a n s f e r r a t e a t f l u i d -s u r f a c e i n t e r f a c e time-averaged p r e s s u r e p r e s s u r e g r a d i e n t parameter, -K/(Cf/2) 312 P r a n d t l number, ucp/y t u r b u l e n t P r a n d t l number,

Momentum and energy transport in the accelerated fully rough turbulent boundary layer

“…The response of smooth wal l boundary layers to acceleration is discussed in the suninary report by Kays and Moffat [4]. Briefly, smooth wall layer dIJ 0, accelera ti ons are charac ter i zed by the acce l era tion param eter , K = -~~~~ -s--.…”

An experimental study on the efficiency of transpiration cooling in laminar and turbulent hypersonic flows

“…This work showed also that the theory of Rubesin cannot be applied for high blowing ratios, at which a homogenous gas injection through the porous material is violated. Further similar fundamental studies on transpiration cooling showed the big potential of this technique for its application on turbine blades and combustion chambers (Luikov 1963;Kays 1972). The capabilities could significantly be extended with porous ceramic composite materials (CMC).…”

Ventilated oscillatory boundary layers

“…0 Kays [1972] shows that transpired turbulent boundary layers seem to respond to local conditions. That is a boundary layer experiencing a sudden change in injection will, following a short period of adjustment, behave as though it had always been subject to that level of injection.…”