Engineering topics

Antar, B. N.

Publications and source records attributed to Antar, B. N..

20 records · Page 2

NASA NTRS1976

On the solution of two-point linear differential eigenvalue problems

A numerical technique is presented for locating the eigenvalues of two point linear differential eigenvalue problems. The technique is designed to search for complex eigenvalues belonging to complex operators. With this method, any domain of the complex eigenvalue plane could be scanned and the eigenvalues within it, if any, located. For an application of the method, the eigenvalues of the Orr-Sommerfeld equation of the plane Poiseuille flow are determined within a specified portion of the c-plane. The eigenvalues for alpha = 1 and R = 10,000 are tabulated and compared for accuracy with existing solutions.

Antar, B. N.↗

NASA NTRS1975

Numerical calculation of finite amplitude effects in unstable laminar boundary layers

A numerical study of one stage of the transition region from laminar to turbulent flow of the boundary layer over a flat plate is performed. Benney-Lin theory is applied to the laminar profile, which is closer to that of the experiment, i.e., the Blasius profile. Several laminar profiles are studied, all belonging to the Falkner-Skan family. The flow is found to depend principally upon the disturbance spanwise wavenumber, beta, whose variation results, in some instances, in a system of counter-rotating vortices, one on top of the other, for the mean secondary flow.

Antar, B. N.↗