Book Description

Systematic numerical solutions of two dimensional and axisymmetrical laminar jet of an incompressible fluid with and without free stream were obtained. The exact numerical solutions were checked with experimental results and similarity solutions for the case without free stream. At far downstream, the numerical solutions approach the values of similarity solution. The numerical solutions give better agreement with experimental data than the similarity solutions. In general, it shows that the boundary layer equation is a good approximation of laminar jet problem provided that the Reynolds number at nozzle exit is not too low. With free stream, the numerical solutions agree with linearized analytic solution if the jet excess velocity is small in comparison with the free stream velocity. The non-linear effects are to decrease the rate of decrease of central velocity of the jet and to broaden the spread of the jet. Also an approximate numerical solution for three dimensional laminar jet is proposed. The accuracy of the method was determined from the exact solutions of the two limiting cases of three dimensional jets, i.e., two dimensional and axisymmetric. It was found that this approximate method may give good results for the axial velocity distribution and the spread of three dimensional jet. (Author).