Hypersonic Viscous Shock Layer Calculation of Leeward Vortex-Induced Heat Transfer on a Sharp Cone at a High Angle of Attack

1977 ◽  
Vol 99 (2) ◽  
pp. 307-313 ◽  
Author(s):  
J. C. Adams

An analysis technique applicable to the problem of leeward vortex-induced heat transfer on a sharp cone at high angles of incidence under hypersonic laminar flow conditions is presented. The analysis, a three-dimensional hypersonic viscous shock layer approach in conjunction with a numerical solution procedure, is shown to be both applicable and accurate based on comparisons of heat-transfer distributions, surface pressure distributions, and leeward meridian flow-field profile measurements taken in a hypersonic wind tunnel. Detailed calculations of the embedded vortex flow field on the leeward side of the cone are presented in such a manner as to clearly portray exactly how embedded vortex flow influences local heating rates.

1998 ◽  
Vol 120 (4) ◽  
pp. 840-857 ◽  
Author(s):  
M. P. Dyko ◽  
K. Vafai

A heightened awareness of the importance of natural convective cooling as a driving factor in design and thermal management of aircraft braking systems has emerged in recent years. As a result, increased attention is being devoted to understanding the buoyancy-driven flow and heat transfer occurring within the complex air passageways formed by the wheel and brake components, including the interaction of the internal and external flow fields. Through application of contemporary computational methods in conjunction with thorough experimentation, robust numerical simulations of these three-dimensional processes have been developed and validated. This has provided insight into the fundamental physical mechanisms underlying the flow and yielded the tools necessary for efficient optimization of the cooling process to improve overall thermal performance. In the present work, a brief overview of aircraft brake thermal considerations and formulation of the convection cooling problem are provided. This is followed by a review of studies of natural convection within closed and open-ended annuli and the closely related investigation of inboard and outboard subdomains of the braking system. Relevant studies of natural convection in open rectangular cavities are also discussed. Both experimental and numerical results obtained to date are addressed, with emphasis given to the characteristics of the flow field and the effects of changes in geometric parameters on flow and heat transfer. Findings of a concurrent numerical and experimental investigation of natural convection within the wheel and brake assembly are presented. These results provide, for the first time, a description of the three-dimensional aircraft braking system cooling flow field.


Author(s):  
Shoichi Kodate ◽  
Tatsuya Kubo ◽  
Shinji Ebara ◽  
Hidetoshi Hashizume

In this study, the characteristic of the swirling flow was analyzed in detail in terms of flow field by means of a visualization experiment using matched refractive index PIV measurement to evaluate the applicability of the swirling flow generated downstream of a three-dimensionally connected dual elbow to the divertor cooling. The dual elbow used in the experiment comprises two 90-degree elbows with the same curvature connected directly in three-dimensional configuration. From the experiment, it was found that strong swirling velocity component appears locally near the pipe wall downstream of the second elbow. Moreover, although the strength of the swirling flow changed gradually as it flowed downstream, it attenuated little even 8D downstream of the dual elbow, where D was the diameter of the piping. Therefore, this swirling flow is expected to survive for a considerable distance downstream of the elbow, and the applicability of this flow field to divertor cooling can be promising. Furthermore turbulence quantities such as Reynolds stress were analyzed in terms of heat transfer performance. Since there were some regions where larger Reynolds stress than a developed turbulent pipe flow was observed near the pipe wall, high heat transfer is expected there.


1985 ◽  
Vol 22 (6) ◽  
pp. 614-619 ◽  
Author(s):  
D. J. Song ◽  
S. Swaminathan ◽  
Clark H. Lewis

2013 ◽  
Vol 397-400 ◽  
pp. 321-325
Author(s):  
Jie Qin ◽  
Ming Yu Zhang

For the problem of one time trajectory correction, a new correction mechanism changing the resistance pieces area is given. The projectile motion locus can be controlled by increasing resistance. In view of the issue of correction trajectory of flying body, the aerodynamic characteristics are changed by the size of resistance ring unfolded area. The comparison between resistance ring flying body and ordinary flying body has been analyzed about the three-dimensional flow field in different sonic. This paper researches related variation and factors of the aerodynamic characteristics with the size of resistance ring unfolded area as a characteristic parameter. The changes of the size of resistance ring unfolded area have a significant impact on resistance coefficient of the flying body. Damping plate affects the part flow field of the flying body and then the whole flow field. On the leeward side of damping plate, there forms the obvious whirlpool area. Due to the low pressure of the whirlpool area, there brings the pressure difference between windward and leeward of the damping plate, and this situation exists in the conditions of subsonic, transonic, and supersonic.


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