Abstract:
An investigation on the approximate solutions of the unsteady
boundary layer equations have been made here by using an
approximate integral method proposed by Bianchini at al. Based on
this method, similarity solutions due to different boundary layer
models are obtained.
For this PUrpose, the potential flow of the basic twodimensional
equations governing the unsteady incompressible laminar
boundary layer flow is, in general, taken to be a function of time
. 't
r
and the longitudinal distance 'x' of the flow. The basic
90verning equations arB then made similar by introducing a
similarity variable with a scale function taken to be a function of
time r t' and 'x'. The introduction of this scale function thus
reduce the basic tWo-dimensional non-linear partial differential
equations to a simple ordinary differential equation.
Based on this differential equation, closed form solutions for
different unsteady cases and the corresponding steady cases are
obtained. These solutions are presented in the form of velocity
profiles. Some of these results show fairly well agreement with
known solutions. In both the unsteady and steady cases mentioned
(i )
above, skin-friction Co-efficlents correspondig to ,the velocity
distributions are also obtained and Compared with known results. In
particular, flate plate boundary layer solutions both for Unsteady
and steady cases show very good agreement with the results showed
by Rosenhead and Blasius respectively.
