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A flow model has been developed to study the flow development after reattachment with supersonic external streams. Special attention is given to the pressure difference across the viscous layer, and it is suggested that such a flow redevelopment can be treated as a relaxation of this pressure difference. Upon correlating the pressure difference with a slope parameter of the velocity profile, the system of equations governing the flow would produce a saddle point singularity corresponding to the fully rehabilitated asymptotic flow condition. A method of calculation for this flowfield, in conjunction with the matching of the upstream flow, has been derived and is discussed. Samples of calculations are also presented. Reasonably good agreement with experimental data has also been observed.

The occurrence of Mach reflection within the over-expanded nozzle free jet flow has been examined. A flow model emphasizing the interaction between the outer and central core streams has been developed to deal with flow situations where detailed inviscid calculations of the flowfield with Mach reflexion are not possible. The results obtained show reasonably good agreement with the available experimental data. This method has also produced comparable results where detailed calculations of the flowfield are possible.

A viscid-inviscid interaction procedure for the calculation of subsonic and transonic flow over a boattail was developed. This method couples a finite-difference inviscid analysis with an integral boundary-layer technique. Results indicate that the effect of the boundary layer is as important as an accurate inviscid method for this type of flow. Theoretical results from the solution of the full transonic-potential equation, including boundary layer effects, agree well with the experimental pressure distribution for a boattail. Use of the small disturbance transonic potential equation yielded results that did not agree well with the experimental results even when boundary-layer effects were included in the calculations.

An analytical study of nonsimilar jet mixing is made for compressible, nonisoenergetic flows. The conservation equations are solved for each of the streams above and below the dividing streamline by using Meksyn's asymptotic method of integration for solving boundary-layer problems. The problem of laminar mixing between two parallel streams is investigated for the case of a constant pressure gradient. It is found that the velocity and temperature profiles from the exact solution to the nonsimilar governing equations can be well approximated by the locally similar solution.

The problem of transonic flow past boattails was studied with the aid of numerical relaxative schemes. Preliminary calculations were restricted to a particular model configuration which had been tested in an experimental program. It was found that the full potential equation must be considered in the study. The final results agreed very well with the experimental data. The investigation illustrates the strong interaction character of the transonic flow past a boattailed afterbody.

The flowfield associated with the underexpanded axisymmetric nozzle freejet flow including the appearance of a Mach disk has been studied. It is shown that the location and size of the Mach disk are governed by the appearance of a triple-point shock configuration and the condition that the central core flow will reach a state of 'choking at a throat'. It is recognized that coalescence of waves requires special attention and the reflected wave, as well as the vorticity generated from these wave interactions, have to be taken accurately into account. The theoretical results obtained agreed well with the experimental data.

An analytic study of the development of an initially nonsimilar jet mixing velocity profile toward the final asymptotic, similar solution, is made. The corresponding incompressible boundary layer equations are solved for each of the streams above and below the dividing streamline by using Meksyn's asymptotic method of integration. The behavior of this flow development toward the final similar solution, as influenced by the initial condition, is properly described and discussed.

Free shear layer similarity flow profiles correlation for turbulent isobaric jet mixing by spread rate parameters, using viscosity models

Theoretical analysis of jet mixing under influence of non-constant pressure gradient

Two dimensional supersonic turbulent free shear layer recompression process from flow model numerical calculation

Flow model for recompression of two dimensional supersonic turbulent free shear layer

Monte Carlo solutions to Boltzmann equation for heat transfer, shock wave, and nonequilibrium gas flow problems

Two-dimensional nonisoenergetic turbulent jet mixing between two compressible streams at constant pressure

Aircraft supersonic ejector system with nonconstant area shroud stressing inviscid and viscid interaction between primary and secondary streams

Quasi-steady flow analysis of transient pumping characteristics of supersonic ejector systems

Performance characteristics and interaction between primary and secondary fluid flow streams of supersonic ejector systems

Procedures for matching intake and ejector pumping characteristics of air-augmented nozzles

Flow pattern within constant pressure compressible turbulent jet mixing region

Influence of heat and mass additions on the base pressures of a wake

Studies are described in which the effort was essentially directed to classes of problems where the phenomenologically interpreted effective transport coefficients could be absorbed by, and subsequently extracted from (by comparison with experimental data), appropriate coordinate transformations. The transformed system of differential equations could then be solved without further specifications or assumptions by numerical integration procedures. An attempt was made to delineate different regimes for which specific eddy viscosity models could be formulated. In particular, this would account for the carryover of turbulence from attached boundary layers, the transitory adjustment, and the asymptotic behavior of initially disturbed mixing regions. Such models were subsequently used in seeking solutions for the prescribed two-dimensional test cases, yielding a better insight into overall aspects of the exchange mechanisms.

Investigation of the Mach reflection associated with a steady two-dimensional overexpanded nozzle flow. The conditions of occurrence of triple point shock configuration are described, and Mach reflection configurations for two values of the incident shock are presented, along with the Mach stem height variation for different Mach numbers under conditions of different pressure ratios.

The application of the method of integral relations to nozzle and ejector flow problems was examined. For nozzle flow problems, the general formulation is that the approaching flow may be rotational. Particular attention was given to the phenomenon of choking under nonuniform flow conditions. Numerical integration of the governing ordinary differential equations was also investigated. This scheme of analysis was also applied to study the interacting flow field within an ejector system.