Download or read book Supersonic Laminar Flow Reattachment and Redevelopment Behind a Two dimensional Rearward Facing Step written by Donald Jacob Spring and published by . This book was released on 1974 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Existence of Three dimensional Perturbations in the Reattachment of a Two dimensional Supersonic Boundary Layer After Separation written by Jean J. Ginoux and published by . This book was released on 1960 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reattachment region of a laminar boundary layer after separation has been investigated at a Mach number of 2.16. Two-dimensional compression corners and backward or forward facing step models were used. The case of interaction between a shock wave and a laminar boundary layer was also considered. Surface flow was observed by a sublimation technique and detailed span-wise surveys were made in the reattachment region of the flow with total-head probes. Strong, regular and repeatable span-wise perturbations were observed in the boundary layer; these could not be explained by irregularities either in the air flow upstream of the models or in the models themselves. It was found in all cases that street-like flow perturbations existedup to the point where transition occurred. A systematic investigation was made on backward facing steps in order to find out the effects of step height and boundary-layer thickness on the wave length of the flow perturbations. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laminar Separation in Supersonic Flow with Emphasis on Three dimensional Perturbations at Reattachment written by Jean J. Ginoux and published by . This book was released on 1960 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SUPERSONIC FLOW SEPARATION ON A BACKWARD FACING STEP written by and published by . This book was released on 1966 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper describes an experimental survey of flow separation on backward facing steps having different heights at a Mach number of 2.4. Reattachment and critical points are found for three regimes, laminar, transitional, and turbulent. Reattachment occurs at a point where the pressure is 35% of the free stream value for turbulent flow, and 60% of this value in the laminar case. The length of the free shear layer is found to be one-half that of the separating streamline, a result which emphasizes the importance of the reattachment region. The flow downstream of the critical point is found to be relatively independent of the base flow. Disturbances in the spanwise direction are always observed in laminar flow but do not affect the base pressure.

Download or read book Base Pressure Behind Two dimensional and Axially Symmetric Backward Facing Steps in a Turbulent Supersonic Flow written by Josef Rom and published by . This book was released on 1963 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The pressure behind a two-dimensional step in supersonic turbulent flow is calculated by the use of the Crocco-Lees momentum integral method. However, instead of assuming a constant mixing rate of k=0.03, it is assumed that C, the average value of turbulent mixing rate correlation function between separation and shock impingement positions, is constant. This assumption considers the turbulent mixing to be similar, in general, to the laminar case except for the much higher mixing rate. The assumption of C, as constant leads to a similarity parameter for the pressure behing a two-dimensional step equal to Re sub L to the minus 3/5 power times h/l. Pressure distribution behind two-dimensional steps is measured at Mach number of 2.25 and Reynolds numbers between 0.35 to 5x Re sub L to the minus 3/5 power times h/l. Good agreement is found between the analytical calculations and the experimental data as well as other published experimental data. Pressure distribution behind axially-symmetric backward facing steps is measured at Mach number 2.25 and Reynolds numbers of 3 to 10 to the 6th power. It is shown that the flow around the axially-symmetric step is similar to that about a free base and is the correlated using the parameter Re sub L to the minus 1/5 power times h/l. Comparison is presented also with published data and good agreement is found. (Author).

Download or read book Preliminary Report on a Study of Separated Flows in Supersonic and Subsonic Streams written by Dean R. Chapman and published by . This book was released on 1956 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some results are described of fundamental research conducted on various flow separation phenomena in two-dimensional streams. Experimental and theoretical results are described for the pressure rise across a reattachment region, and for the Reynolds number dependence of the pressure rise to a separation point. Observations are made throughout of the location of transition relative to reattachment and to separation, since this relative location turned out to be the dominant variable investigated.

Download or read book Numerical Solution of the Navier stokes Equations for the Laminar Supersonic Flow Over a Two dimensional Backward Facing Step written by Y. Kronzon and published by . This book was released on 1974 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book LAMINAR SEPARATION IN SUPERSONIC FLOW written by Jean J. Ginoux and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of three-dimensional flow perturbations in laminar supersonic flows was made on flat plates with sweptback leading edges and in the reattachment region of the flow over flat plates with backward-facing steps. It was shown that a cross-flow existed in the boundary layer on flat plates with supersonic sweptback leading edges of small bluntness, which increased in magnitude from the centerline towards the sides of the models. In separated flows, only an extremely small amount of cross-flow was needed to destabilize the flow and to create regular spanwise variations in total pressure. Larger cross-flows, controlled by a systematic variation of the angle of sweep either of the leading edge or of the edge of the step, had no further effect. Detailed surveys made in a reattaching laminar supersonic flow with a static probe showed that the three-dimensional perturbations that existed in the boundary layer were formed by two layers of equidistant contra-rotating streamwise vortices: one located near the wall and a second one near the outer edge of the boundary layer. (Author).

Download or read book U S Government Research Reports written by and published by . This book was released on 1964 with total page 1600 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Study of Supersonic Flow Over Backward Facing Steps at High Reynolds Number written by Odus R. Burggraf and published by . This book was released on 1970 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of laminar separated flow over a backward-facing step is solved numerically for the limiting case of infinite Reynolds number. The flow model adopted is that deduced by Batchelor for incompressible flow: an inviscid rotational eddy confined within the recirculation portion of the separated shear layer. It is argued that the reattachment process is essentially inviscid in the limit R approaches infinity, and the flow field in the reattachment zone is computed on this basis. The computed results support Chapman's model of the reattachment process as the correct limit case, to second-order accuracy, as the flow angle entering the reattachment zone approaches zero. For the recirculation zone, the boundary-layer equations are simplified by assuming a constant pressure eddy. The Dorodnitsyn transformation is applied and numerical solutions obtained using an implicit finite-difference scheme. The solutions are carried out from station-to-station in the direction of flow over a complete cycle of recirculation. Iteration yields the unique value of the vorticity in the inviscid layer upstream of separation, including the effects of corner expansion and recirculation on the development of the separated shear layer. (Author).

Download or read book Turbulent Boundary layer Temperature Recovery Factors in Two dimensional Supersonic Flow written by Maurice Tucker and published by . This book was released on 1951 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical method is presented for obtaining turbulent temperature recovery factors for a thermally insulated surface in supersonic flow. The method is an extension of Squire's analysis for incompressible flow. The boundary layer velocity profile is represented by a power law and a similarity is postulated for squared-velocity the static-temperature-difference profiles.

Download or read book Turbulent Flow Reattachment written by John K. Eaton and published by . This book was released on 1980 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Basic Engineering written by and published by . This book was released on 1970 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Survey of Rearward facing Steps in Two Dimensional Supersonic Flow written by Alan W. Myers and published by . This book was released on 1967 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laminar Separation in Supersonic and Hypersonic Flows written by Jean J. Ginoux and published by . This book was released on 1965 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: High speed two-dimensional reattaching flows are characterized by the development of regularly spaced vortices in the boundary layer, whose effect is to produce heat transfer rates at reattachment which are, locally over the span, considerably higher in laminar and transitional flows than in the turbulent case. These results are expected to occur both at supersonic and hypersonic speeds, as these vortices were observed over a range of Mach numbers of 1.5 to 7.0. A basic difference in the recovery of total energy at reatachment was observed between laminar and transitional flows over ramps. In the latter case, the recovery temperature was maximum at reattachment and decreased to the laminar theoretical value in a region downstream of reattachment, where the flow was turbulent. The aerodynamic heating of sweptback wings can be predicted by a simple method derived from flat plate theory and by superimposing flow components parallel and perpendicular to the leading edge. Streamwise vortices do not seem to affect the average heat transfer coefficient. (Author).