Investigation of Combined Low-Angled Jets and Variable Wall Geometry for Hypersonic Aerodynamic Control

2000 ◽  
Author(s):  
Rodney D. Bowersox ◽  
Huaiguo Fan
Keyword(s):  
Aerodynamic Control ◽  
Variable Wall ◽  
Wall Geometry

scholarly journals Study On The Single Point Incremental Sheet Forming of AISI 321 Variable Wall Angle Geometry

2021 ◽  
Author(s):  
Muhammad Jawad Afzal ◽  
Asif Israr ◽  
Muhammad Soban Akram ◽  
Abdul Muqeet
Keyword(s):  
Low Cost ◽  
Single Point ◽  
Cnc Machine ◽  
Forming Process ◽  
Wall Angle ◽  
Metal Forming Process ◽  
Clamping System ◽  
Variable Wall ◽  
Aisi 321 ◽  
Wall Geometry

Abstract For rapid prototyping, design validation and small batch productions process with low tooling cost is preferred. Single Point Incremental Forming (SPIF) is a die-less sheet metal forming process which requires only low cost forming tool driven by CNC machine in a toolpath to form required geometry at room temperature from sheet blank clamped in a low cost and low stiffness clamping system. In this study, effect of process parameters such as tool radius, feed rate and lubrication are considered on the formability of the truncated profile of AISI 321 Variable Wall Geometry (VWA). Set parameters conditions with 2 level layers are optimized using numerical and statistical approach. Experimentation on the same setup is carried out by selecting the most, least and mid favorable solutions optimized on the basis of forming forces and stresses in the sheet. Geometrical accuracy, sheet thinning, and forming forces are compared analytically, numerically and experimentally addressing the inadequacy of analytically models for Variable Wall Angle Geometries.

scholarly journals Extrusion of magnesium alloy hollow profiles with axial variable wall thickness

2019 ◽  
Author(s):  
Maik Negendank ◽  
Vidal Sanabria ◽  
Sören Müller ◽  
W. Reimers
Keyword(s):  
Magnesium Alloy ◽  
Wall Thickness ◽  
Variable Wall Thickness ◽  
Variable Wall

MEMS for aerodynamic control

1997 ◽  
Author(s):  
Motoaki Kimura ◽  
Steve Tung ◽  
Chih-Ming Ho ◽  
Fukang Jiang ◽  
Yu-Chong Tai ◽  
...  
Keyword(s):  
Aerodynamic Control

scholarly journals Large scale experimental study on the fire hazard of buildings’ U-shape façade wall geometry

2017 ◽  
Vol 23 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Weigang YAN ◽  
Lin JIANG ◽  
Weiguang AN ◽  
Yang ZHOU ◽  
Jinhua SUN
Keyword(s):  
Theoretical Analysis ◽  
Flame Spread ◽  
Large Scale ◽  
Fire Hazard ◽  
Residential Building ◽  
Flame Height ◽  
Geometrical Factor ◽  
Insulation Material ◽  
Upward Flame Spread ◽  
Wall Geometry

Buildings have U-shape façade designs for certain purposes such as lighting. However, such designs may lead to a higher fire hazard. In this paper, large scale experiments of upward flame spread over XPS insulation material were conducted to investigate the fire hazard of building’s U-shape façade wall geometry. Comparison to previous labora­tory scale experiments were also presented. Theoretical analysis was performed to reveal the mechanism of the U-shape geometry’s influences. It is found that such geometry design would increase the fire hazard of buildings: flame spread rate and flame height increased with U-shape’s geometrical factor. The results agreed with theoretical analysis. It is ex­pected that the buildings’ U-shape façade wall geometry would greatly benefit flame spread for full scale applications and increase the fire hazard. Thus engineers should be careful with such façade wall designs, especially for residential building designs.

Exploring research on high-speed vehicle attitude control with plasma virtual flap manipulation

2018 ◽  
Vol 233 (10) ◽  
pp. 3627-3634
Author(s):  
Wang Xin ◽  
Yan Jie ◽  
Zhang Yerong
Keyword(s):  
Attitude Control ◽  
High Speed ◽  
Long Duration ◽  
Aerodynamic Control ◽  
Control Authority ◽  
Attitude Controller ◽  
Lift And Drag ◽  
Cruise Flight ◽  
Aerodynamic Lift ◽  
High Speed Vehicle

This work provides an attitude solution for a high-speed vehicle using plasma aerodynamic control called “plasma virtual flap” manipulation. This paper describes the concept of using plasma active control as plasma virtual flap for off-design attitude manipulation problem. Design of an attitude controller considering plasma aerodynamic effects for the high-speed vehicle is presented. The aerodynamic lift and drag force features in the high speed, long duration cruise flight with plasma actuator effect are introduced, where the estimated models and attitude controller are established. This paper documents the development and capabilities of plasma virtual flap attitude control authority. Simulation results are presented to exhibit the effectiveness of the proposed method.

Gaseous detonation propagation in a bifurcated tube

2008 ◽  
Vol 599 ◽  
pp. 81-110 ◽  
Author(s):  
C. J. WANG ◽  
S. L. XU ◽  
C. M. GUO
Keyword(s):  
Numerical Simulation ◽  
Detonation Wave ◽  
Mach Reflection ◽  
Initial Pressure ◽  
Gaseous Detonation ◽  
Recirculation Region ◽  
Horizontal Branch ◽  
Regular Reflection ◽  
Detonation Propagation ◽  
Wall Geometry

Gaseous detonation propagation in a bifurcated tube was experimentally and numerically studied for stoichiometric hydrogen and oxygen mixtures diluted with argon. Pressure detection, smoked foil recording and schlieren visualization were used in the experiments. Numerical simulation was carried out at low initial pressure (8.00kPa), based on the reactive Navier–Stokes equations in conjunction with a detailed chemical reaction model. The results show that the detonation wave is strongly disturbed by the wall geometry of the bifurcated tube and undergoes a successive process of attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection. Detonation failure is attributed to the rarefaction waves from the left-hand corner by decoupling leading shock and reaction zones. Re-initiation is induced by the inert leading shock reflection on the right-hand wall in the vertical branch. The branched wall geometry has only a local effect on the detonation propagation. In the horizontal branch, the disturbed detonation wave recovers to a self-sustaining one earlier than that in the vertical branch. A critical case was found in the experiments where the disturbed detonation wave can be recovered to be self-sustaining downstream of the horizontal branch, but fails in the vertical branch, as the initial pressure drops to 2.00kPa. Numerical simulation also shows that complex vortex structures can be observed during detonation diffraction. The reflected shock breaks the vortices into pieces and its interaction with the unreacted recirculation region induces an embedded jet. In the vertical branch, owing to the strength difference at any point and the effect of chemical reactions, the Mach stem cannot be approximated as an arc. This is different from the case in non-reactive steady flow. Generally, numerical simulation qualitatively reproduces detonation attenuation, failure, re-initiation and the transition from regular reflection to Mach reflection observed in experiments.

Wind-induced responses of tall buildings under combined aerodynamic control

2018 ◽  
Vol 175 ◽  
pp. 86-100 ◽  
Author(s):  
Chaorong Zheng ◽  
Yu Xie ◽  
Mahram Khan ◽  
Yue Wu ◽  
Jing Liu
Keyword(s):  
Tall Buildings ◽  
Induced Responses ◽  
Aerodynamic Control
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