We discuss the development of a simplified model for the jet noise source that can be used in practical predictions of installed noise. In the proposed scheme, the source is prescribed on a radiator surface defining the boundary between the inner rotational jet flow and the outer linear pressure field. The source consists of wavepacket-type partial fields whose noise propagation can be computed...

Direct numerical simulations (DNSs) of spatially developing thermal turbulent boundary layers over angle-ribbed walls were performed. Four rib angles (γ=90°,60°,45° and 30°) examined. It was found that the 45° ribs produced highest drag coefficient, whereas 30° most improved Stanton number. In comparison to transverse case, streamwise velocity dimensionless temperature in V-shaped cases signifi...

This paper presents a comprehensive analysis of the momentum and energy transfer in compressible turbulent boundary layers based on integral identities. By considering data obtained from direct numerical simulations for wide parameter range, superordinate influences compressibility, wall heat pressure gradient terms governing equations are identified visualized. allows us both to determine what...

Drawing on an analogy to critical phenomena, it was shown that the Nikuradse turbulent friction factor (ft) measurements in pipes of radius R and wall roughness r can be collapsed onto a one-dimensional curve expressed as conveyance law ftRe1/4=go(?), where Re is bulk Reynolds number ?=Re3/4(r/R). The implicit function go(.) conjectured based matching two asymptotic limits ft. However, connecti...

The influence of Reynolds number on the performance of outboard spoilers and ailerons was investigated on a generic subsonic transport configuration in the National Transonic Facility over a chord Reynolds number range from 3 to 30 million and a Mach number range from 0.70 to 0.94. Spoiler deflection angles of 0, 10, and 20 degrees and aileron deflection angles of -10, 0, and 10 degrees were te...