Showing papers by "James D. Iversen published in 1973"

Correlation of Magnus Force Data for Slender Spinning Cylinders

Abstract: Time-dependent results of numerical finite-difference solution for the two-dimensional spinning circular cylinder are used to derive a correlation parameter for analysis of experimental Magnus force data. The correlation parameter, which is a function of angle of attack, the fineness ratio, and the Reynolds number, is derived on the basis of the impulse or cross-flow analogy. The correlation parameter, derived for finless slender spinning circular cylinders is shown to successfully correlate experimental data for fineness ratios from 6 to 24, for subsonic through supersonic freestream speeds, and for cross-flow Mach numbers up to 0.4 at transonic and supersonic speeds. Cy = Cyp = d = k = / = M p p t t/oo Uc V x 7 a v p Nomenclature two-dimensional lift coefficient, lift per unit span/(l/2)p Uc2 d local side-force coefficient, side-force per unit span/(l/2)p Uc2 d = Magnus force coefficient, 87/pl/^2 nd2p = body diameter = constant of proportionality = body length = freestream Mach number = spin rate = dimensionless spin rate, pd/211^ = time = freestream speed = component of freestream speed normal to body axis = tangential surface speed due to spin = distance along body axis from nose = Magnus force = angle of attack = kinematic viscosity = air density