Three-dimensional wings in hypersonic flow

1972 ◽  
Vol 54 (2) ◽  
pp. 305-337 ◽  
Author(s):  
R. Hillier
Keyword(s):  
Exact Solution ◽  
Hypersonic Flow ◽  
Shock Layer ◽  
Three Dimensional ◽  
Leading Edge ◽  
The Other ◽  
Calculation Methods ◽  
Conical Flow ◽  
Thin Shock Layer ◽  
Good For

Messiter's thin shock layer approximation for hypersonic wings is applied to several non-conical shapes. Two calculation methods are considered. One gives the exact solution for a particular three-dimensional geometry which possesses a conical planform and also a conical distribution of thickness superimposed upon a surface cambered in the chordwise direction. Agreement with experiment is good for all cases, including that where the wing is yawed. The other method is a more general approach whereby the solution is expressed as a correction to an already known conical flow. Such a technique is applicable to conical planforms with either attached or detached shocks but only to the non-conical planform for the region in the vicinity of the leading edge when the shock is attached.

Hypersonic Flow Over Conical Wing-Body Combinations

1978 ◽  
Vol 29 (4) ◽  
pp. 285-304 ◽  
Author(s):  
R. Hillier
Keyword(s):  
Hypersonic Flow ◽  
Shock Layer ◽  
The Body ◽  
Practical Computation ◽  
Comparison With Experiment ◽  
Thin Shock Layer ◽  
Slope Discontinuity ◽  
The Common ◽  
Good For ◽  
Conical Wing

SummaryThis paper shows how thin shock layer theory may be applied to wing-body combinations and also to yawed wings of caret and diamond section. The common feature of these cases is the interaction of the crossflow with the body slope discontinuity and the manner in which the resulting disturbances propagate through the shock layer. Practical computation of surface pressures is straightforward and comparison with experiment appears to be fairly good for the limited results available.

Hypersonic Flow with Attached Shock Waves over Delta Wings

1970 ◽  
Vol 21 (4) ◽  
pp. 379-399 ◽  
Author(s):  
B. A. Woods
Keyword(s):  
Shock Waves ◽  
Hypersonic Flow ◽  
Shock Layer ◽  
Numerical Solutions ◽  
Delta Wing ◽  
Simple Wave ◽  
Delta Wings ◽  
Conical Flows ◽  
Thin Shock Layer ◽  
Flow Variables

SummaryHypersonic conical flows over delta wings are treated in the thin-shock-layer approximation due to Messiter. The equations are hyperbolic throughout, even in regions where the full equations are elliptic, and have not hitherto been solved for flows with attached shock waves. The concept of the simple wave has been used to construct a class of solutions for such flows; they contain discontinuities in flow variables and shock slope but, for the case of flow over a delta wing with lateral symmetry, agreement with results of numerical solutions of the full equations is good. The method is applied to plane delta wings at yaw, and to wings with anhedral and dihedral. For the flow at the tip of a rectangular wing, it is shown that two distinct solutions may be constructed.

Flow Regimes over Delta Wings at Supersonic and Hypersonic Speeds

1976 ◽  
Vol 27 (1) ◽  
pp. 1-14 ◽  
Author(s):  
L C Squire
Keyword(s):  
Shock Layer ◽  
Delta Wing ◽  
Leading Edge ◽  
Flow Regimes ◽  
Lower Surface ◽  
Delta Wings ◽  
Thin Shock Layer ◽  
Wide Range ◽  
Wing Sweep ◽  
Edge Separation

SummaryThis paper concerns the boundaries between flow regimes for sharp-edged delta wings in supersonic flow and the relation of some predictions of thin-shock-layer theory to these boundaries. In particular, it is shown that the theory predicts that the attachment lines on the lower surface of a thin delta wing at supersonic speeds suddenly jump from just inboard of the leading edges to the centre line in certain flight conditions. In general there is close agreement between the conditions for this jump and the flight conditions corresponding to the change-over from attached flow to the leading-edge separation on the upper surface. Since the movement of the attachment lines on the lower surface must change the position of the sonic line and the nature of the expansion around the edge, it is suggested that the two phenomena are directly related. Thus thin-shock-layer theory can be used to establish the boundaries of the various flow regimes for a wide range of Mach number, incidence and wing sweep. The theory can also be used to predict the effects of wing thickness on leading-edge separation, but here the experimental data is very sparse and somewhat contradictory, so the value of the prediction in the case of thickness requires further investigation.

Three-Dimensional Structure of a Nominally Planar Turbulent Boundary Layer

1979 ◽  
Vol 101 (3) ◽  
pp. 326-330 ◽  
Author(s):  
Y. Furuya ◽  
I. Nakamura ◽  
H. Osaka
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Three Dimensional ◽  
Leading Edge ◽  
Turbulent Boundary Layers ◽  
Main Flow ◽  
The Other ◽  
Dimensional Structure ◽  
Spanwise Direction ◽  
Streamwise Vortices

This research is concerned with detailed experiments on spanwise nonuniformity of nominally planar turbulent boundary layers. Two procedures for eliminating spanwise nonuniformity are studied. One method is to remove the original, natural vortices by introducing additional ones arising from protuberances attached to the leading edge of a flat plate, and the other technique is by making the main flow entirely uniform. Effects of artificially controlled streamwise vortices on spanwise nonuniformity are examined. From these experiments, the process by which induced vortices cause nonuniformity of turbulent boundary layer characteristics in the spanwise direction is discussed.

Hypersonic flow with attached shock waves over plane delta wings

1977 ◽  
Vol 79 (2) ◽  
pp. 361-377 ◽  
Author(s):  
B. A. Woods ◽  
C. B. G. Mcintosh
Keyword(s):  
General Solution ◽  
Shock Waves ◽  
Hypersonic Flow ◽  
Shock Layer ◽  
Delta Wing ◽  
Numerical Calculations ◽  
Delta Wings ◽  
Thin Shock Layer ◽  
New Form

A new form is given for the general solution to the thin-shock-layer equations for the flow over a nearly plane delta wing. Using this, the solution described conjecturally by Hayes & Probstein for symmetrical flow with attached shock waves over a plane delta wing is realized numerically. The flow construction devised for this purpose is applied also to yawed flows. The solutions obtained are found to agree moderately well with the results of numerical calculations from the full equations, but contain a number of anomalous features characteristic of the thin-shock-layer approximation.

Experimental Contribution on the Significance and the Control by Transverse Injection of the Horseshoe Vortex

1996 ◽  
Author(s):  
D. P. Georgiou ◽  
V. A. Papavasilopoulos ◽  
M. Alevisos
Keyword(s):  
Bluff Body ◽  
Delta Wing ◽  
Three Dimensional ◽  
Leading Edge ◽  
Horseshoe Vortex ◽  
The Other ◽  
Injection Velocity ◽  
Pressure Losses ◽  
Vortex Size ◽  
Transverse Injection

The present study addresses two aspects of the horseshoe vortex, namely its significance in the secondary flow in a turbine blade passage and the possibility of reducing its strength by an active flow mechanism, i.e the transverse injection of coolant air through a slot in a cylinder-endwall junction. The study reports on the results of two experiments in low speed wind tunnels, which employed a calibrated five-hole Pitot tube to measure the velocity vectors and the resulting secondary flowfields. The first aspect was studied in a 90° square cross section bend duct. The two horseshoe vortex legs were simulated by two half-Delta wing vortex generators. The results showed that the horseshoe vortices influence two regions of the secondary flowfield, i.e one near the passage entrance, where the pressure side leg forces a three dimensional separation of the endwall boundary layer, and the other is in the exit plane, where the coupling of the horseshoe with the passage vortex redistributes the flow with total pressure losses, without affecting the total loss, and increases the secondary kinetic energy by about 20%. For the second aspect, a rectangular bluff body, with a cylindrical leading edge, was positioned over the tunnel endwall and the transverse air injection was implemented through a thin slot, covering the 180° arc in the leading edge-endwall junction. The results showed that, for an average injection velocity equal to 35% that of the mainstream, the size and strength of the horseshoe vortex leg were reduced by nearly 60%. On the other hand, for stronger injection rates the vortex size and strength were increased.

Three-Dimensional Reconstruction of Two Forms of the Chaperonin GRO EL

1990 ◽  
Vol 48 (1) ◽  
pp. 258-259
Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Series Method ◽  
Three Dimensional Reconstruction ◽  
Structural Components ◽  
E Coli ◽  
Dimensional Reconstruction ◽  
Morphogenetic Factors ◽  
Tilt Series

Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.

INFLUENCE OF THE PLATE LEADING-EDGE SHAPE AND THICKNESS ON THE BOUNDARY LAYER LAMINAR-TURBULENT TRANSITION IN HYPERSONIC FLOW

2019 ◽  
Vol 50 (5) ◽  
pp. 461-481
Author(s):  
Sergei Vasilyevich Aleksandrov ◽  
Evgeniya Andreevna Aleksandrova ◽  
Volf Ya. Borovoy ◽  
Andrey Vyacheslavovich Gubernatenko ◽  
Vladimir Evguenyevich Mosharov ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Hypersonic Flow ◽  
Leading Edge ◽  
Turbulent Transition ◽  
Laminar Turbulent Transition
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