A similarity analysis is presented mainly of the outside flow region of a turbulent plane wall jet which flows along a flat surface placed in otherwise quiet surroundings.
Experiments about wall jets have revealed that the point of zero shear stress lies nearer the wall than the point of maximum velocity. This is one example of flows which have the countergradient shear stress region.
Taking into account such an observation, REYNOLDS shear stress is expressed in the form including the second order term, like τ∞-υ(lU_y+0.5ll²U_yy).The coeficients of U_y and U_yy are assumed to be proportional to bυ' and b³υ_y', respectively, where b is the half-value thickness of jets, and υ' the lateral turbulence intensity and its distribution is given by experimentally observed data.
Specifying some values at the point of maximum velocity, integration of a fourth-order differential equation is carried out first toward the edge of the jet, next to the inner flow region. Calculated distributions about velocity and shear stress are compared fairly well with some measurements except for the near wall region.