Drag-reduction performance of riblets on an axi-symmetric body was investigated using ARE’s High Speed Buoyancy Propelled Vehicle (MOBY-D) at high Reynolds number. Approximately 35% of the wetted body surface was applied with riblets in situ using BMT’s RIBCOATTM process, and net drag reductions between 0 and 3.0% were observed during the flight. The drag reduction increased toward the ascent as the vehicle acceleration decreased, indicating that the favourable effects that riblets have on the boundary layer structure may be susceptible to acceleration.

The unsteady loads on two wings, one exhibiting a trailing edge separation, the other a leading edge separation have been measured. It has been found that there are differences between the two wing loads, one having a large scale viscous-inviscid interaction producing high loads at a low frequency.

Holography is a very powerful tool for studying compressible flows. It is a non-intrusive technique capable of both qualitative and quantitative assessment. This paper describes a number of applications to both two-dimensional and three-dimensional flow fields.

The solution of sandwich plate problems by the framework method is proposed and the basic elements of the method used are reviewed. The technique is demonstrated by application to a simple framework analog for rectangular sandwich panels with very thin faces and an antiplane core. A number of illustrative examples involving small and large deflections are solved.