A Critical Review of Analytical Methods for Estimating Control Forces Produced by Secondary Injection


Book Description

The problem discussed is that of theoretically predicting the normal force induced in the boundary layer separation region immediately ahead of a secondary injection port. Attention was limited to the two-dimensional problem of sonic or supersonic normal injection into supersonic or hypersonic mainstreams. A critical review of available experimental studies was conducted in order to isolate those data best representing a two-dimensional state. The resulting compilation of experimental results was thereafter employed as a basis of comparison for available theoretical and empirical flow models. As a result it was found that analytical means are only capable of rough quantitative estimates of control jet effectiveness and that a more detailed flow model is needed to further explain observed phenomenon. The basic features of such a model are formulated and its conceptual validity demonstrated through comparison with experimental results. Problem areas requiring further research are also discussed in detail. (Author).







Two-dimensional Jet Interaction with a Mach 4 Mainstream


Book Description

The report describes the results of an experimental study concerning the injection of a gaseous secondary jet into an unbounded supersonic flow field which was uniform outside of a turbulent boundary layer. The investigation was principally concerned with the definition of the proper scale length to be associated with turbulent two-dimensional jet-interaction flows. In support of this objective, results are presented for a Mach 4 test conducted using a flat-plate model containing a sonic secondary jet directed normal to the mainstream. Secondary jet strengths were varied from approximately 0 to 1000 for jet throat sizes of 0.005 inch, 0.020 inch and 0.030 inch. The jet interaction phenomenon was studied using detailed surface pressure distributions measured fore and aft of the secondary jet in conjunction with comprehensive shadowgraph coverage of the interaction flow field. (Author).




Slot Jet Interaction Studies of an Ogive Cylinder at M[infinity]


Book Description

An experimental study of the control forces and moments generated by a slot-type secondary jet located near the base of an ogive cylinder in a Mach 4 and 5 free stream was conducted in the NOL Supersonic Tunnel No. 2. The free-stream Reynolds number, based on body length, was held constant at 22,000,000 and the missile angle of attack was varied from -10 to +10 degrees. The jet slot spanned one quadrant of the cylindrical surface and was contained between two low aspect ratio fins. (Author).
















Control of Flow Separation


Book Description