An investigation of the exact solutions of the linearized equations for the flow past conical bodies,

Reproduced from type-written copy.

A study of finite-difference methods as applied to hypersonic viscous shock-layer equations

"Contract no. Nonr 2653(00)."

Proceedings of the SCAR Conference, held at Langley Research Center, Hampton, Virginia, November, 9-12, 1976. --

Includes bibliographical references.

Vector polar method for shock interactions with area disturbances /

"AFOSR TN 59-701. Contract no. AF49(638)-166. I. E. R. project no. 96895."

Drag due to lift of a not-so-slender configuration; application of theory.

"Contract no. AF 33(616)-2933."

Airborne simulation for the SST.

Cover title.

On the use of impact theory for slender configurations exhibiting flow separation /

Photocopy.

Nonsteady discharge of subcritical flow /

At head of title: Project SQUID, a cooperative program of fundamental research as related to jet propulsion, Office of Naval Research, Department of the Navy. Contract Nonr 1858 (25), NR-098-038.

Investigation of small surface protuberances upstream of turbulent boundary layer separation produced by a skewed shock wave at Mach 3 /

"Interim report for period January 1976-February 1976."

Can fundamental shock-wave/boundary-layer interaction research be relevant to inlet aerodynamics?

The important influence of shock waves on supersonic inlet performance has led to much time and effort being expended in the area of shock wave/boundary layer interaction research (SWBLI) and SWBLI control. In this short review, the impact of SWBLIs on supersonic inlet aerodynamic research is discussed and is contrasted with fundamental SWBLI research. Inlet research focussed on internal flow performance is reviewed, based on the salient results, conclusions, and the limitations of such work. The role of fundamental SWBLI research in relation to supersonic inlet research is considered, and the possible positive impact of improving the link between fundamental SWBLI research and inlet design is considered. A simple flow-field is discussed which is thought to be able to simulate at least some more of the flow physics found in a typical inlet. A brief review of real inlet parameters is then given to help determine appropriate fundamental experimental parameters such as incoming Mach number, incoming boundary-layer thickness and subsonic difiuser angle. Copyright © 2012 by N. Titchener, H. Babinsky, and E. Loth.

Parametric study of different fins for a rocket at supersonic flow

Various parameters including the fins with variable span to chord ratio, curvature radius, and setting angle have been investigated between the flat fin and wrap around fin (WAF) rocket configurations at supersonic flow. The results show that under the same flight condition, the flat fins can provide a higher lift and pitching moments than the WAFs. Due to the symmetric effect, any extra side forces, moments as well as the self-induced rolling characteristics will be not generated as compared to the WAF configurations. The WAFs can greatly improve the longitudinal stability and enhance the longitudinal aerodynamic characteristics for the whole rocket. The static pressure distributions at different chordwise positions together with the force variations around the fins have been obtained computationally and analyzed in detail.

Chemiluminescence imaging in supersonic combustors operating in radical-farming mode

Emission spectroscopy was used to investigate ignition and combustion characteristics of supersonic combustion ramjet engines. Two-dimensional scramjet models with inlet injection, fuelled with hydrogen gas, were used in the study. The scramjet engines were configured to operate in radical farming mode, where combustion radicals are formed behind shock waves reflected at the walls. The chemiluminescence emission signals were recorded in a two-dimensional, time-integrated fashion to give information on the location and distribution of the radical farms in the combustors. High signal levels were detected in localised regions immediately downstream of shock reflections, an indication of localised hydroxyl formation supporting the concept of radical farming. Results are presented for a symmetric as well as an asymmetric scramjet geometry. These data represent the first successful visualisation of radical farms in the hot pockets of a supersonic combustor. Spectrally resolved measurements have been obtained in the ultraviolet wavelength range between 300 and 400 nm. This data shows that the OH! chemiluminescence signal around 306nm is not the most dominant source of radiation observed in the radical farms.

Supersonic flutter of composite skin panels of repeated-sublaminate layup

In high-speed aerospace vehicles, supersonic flutter is a well-known phenomenon of dynamic instability to which external skin panels are prone. In theory, the instability stage is expressed by the 'flutter critical parameter' Q(crit), which is a function of the stiffness-, and dynamic pressure parameters. For a composite skin panel, Q(crit) can be maximised by lay-up optimisation. Repeated-sublaminate lay-up schemes possess good potential for economical lay-up optimisation because the corresponding effort is limited to a family of sublaminates of few layers only. When Q(crit) is obtained for all sublaminates of a family, and the sublaminates ranked accordingly, the resulting ranking reveals not only the optimum lay-up, but also the near-optimum lay-ups, which are useful design alternatives, and the inferior lay-ups which should be avoided. In this paper, we examine sublaminate-ranking characteristics for a composite panel prone to supersonic flutter. In particular, we consider a simple supported midplane-symmetrical rectangular panel of typical aspect ratio alpha and flow angle psi, and for four-layered sublaminates, obtain the Q(crit)-based rankings for a wide range of the number of repeats, r. From the rankings, we find that an optimum lay-up can exist for which the outermost layer is oriented wide of, rather than along, the flow. Furthermore, for many lay-ups other than the optimum and the inferior, we see that as r increases, Q(crit) undergoes significant change in the course of converging. To reconcile these findings, eigenvalue-coalescence characteristics are discussed in detail for specific cases.