Forebody Geometry Effects on the Flow of a Blunt-Nose Projectile at High Alpha

2007 ◽  
Vol 44 (6) ◽  
pp. 1906-1922 ◽  
Author(s):  
Javier Lopera ◽  
T. Terry Ng ◽  
Mehul P. Patel ◽  
Russ Stucke
Keyword(s):  
Geometry Effects ◽  
Blunt Nose

Magnetic Field and Geometry Effects on Finding Plasma Potential with a Cylindrical Impedance Probe

2012 ◽  
Author(s):  
David N. Walker ◽  
R. F. Fernsler ◽  
D. D. Blackwell ◽  
W. E. Amatucci
Keyword(s):  
Magnetic Field ◽  
Plasma Potential ◽  
Impedance Probe ◽  
Geometry Effects

Thermal and structural response of aerospike mounted on blunt-nose body

2020 ◽  
pp. 095441002097648
Author(s):  
Zhang ZhunHyok ◽  
Won CholJin ◽  
Ri CholUk ◽  
Kim CholJin ◽  
Kim RyongSop
Keyword(s):  
Aerodynamic Force ◽  
Coupling Effect ◽  
Angle Of Attack ◽  
Structural Response ◽  
Response Characteristic ◽  
Wave Drag ◽  
Hypersonic Vehicle ◽  
Loosely Coupled ◽  
Calculation Results ◽  
Blunt Nose

The inclusion of aerospike on blunt nose body of hypersonic vehicle has been considered to be the simplest and most efficient technique for a concurrent reduction of both aeroheating and wave drag due to hypersonic speed. However, the thermal and mechanical behavior of aerospike structure under the coupling effect of aerodynamic force and aeroheating remains unclear. In this study, the thermal and structural response of aerospike mounted on the blunt nose body of hypersonic vehicle was numerically simulated by applying 3 D fluid-thermal-structural coupling method based on loosely-coupled strategy. In the simulation, the angle-of-attack and the spike’s length and diameter are differently set as α = 0°–10°, L/D = 1–2 and d/D = 0.05–0.15, respectively. Through the parametric study, the following results were obtained. Firstly, the increase of vehicle’s angle-of-attack and spike’s length unfavorably affect the thermal and structural response of aerospike. Secondly, the increase of spike’s diameter can improve its structural response characteristic. Finally, the aerospike with the angle-of-attack of 0° and the length and diameter of L/D = 1 and d/D = 0.15, respectively, is preferred in consideration of the effect of flight angle-of-attack and spike’s geometrical structure on the thermal and structural response of spike and the drag reduction of vehicle. The numerical calculation results provide a technical support for the safe design of aerospike.

Flow Geometry Effects on the Turbulent Mixing Efficiency

2006 ◽  
Vol 128 (4) ◽  
pp. 874-879 ◽  
Author(s):  
Roberto C. Aguirre ◽  
Jennifer C. Nathman ◽  
Haris C. Catrakis
Keyword(s):  
Shear Layer ◽  
Turbulent Mixing ◽  
Large Scale ◽  
Mixture Fraction ◽  
Mixing Efficiency ◽  
Developed Turbulence ◽  
Planar Shear ◽  
Flow Geometry ◽  
Schmidt Numbers ◽  
Geometry Effects

Flow geometry effects are examined on the turbulent mixing efficiency quantified as the mixture fraction. Two different flow geometries are compared at similar Reynolds numbers, Schmidt numbers, and growth rates, with fully developed turbulence conditions. The two geometries are the round jet and the single-stream planar shear layer. At the flow conditions examined, the jet exhibits an ensemble-averaged mixing efficiency which is approximately double the value for the shear layer. This substantial difference is explained fluid mechanically in terms of the distinct large-scale entrainment and mixing-initiation environments and is therefore directly due to flow geometry effects.

Strakes Effects on Asymmetric Flow Over a Blunt-Nosed Slender Body at a High Angle of Attack

2018 ◽  
Vol 141 (6) ◽  
Author(s):  
Qihang Yuan ◽  
Yankui Wang ◽  
Zhongyang Qi
Keyword(s):  
Angle Of Attack ◽  
Slender Body ◽  
Axial Position ◽  
High Angle ◽  
Asymmetric Flow ◽  
High Angle Of Attack ◽  
Side Force ◽  
Asymmetric Vortices ◽  
High Angles Of Attack ◽  
Blunt Nose

In general speaking, the missiles execute flight at high angles of attack in order to enhance their maneuverability. However, the inevitable side-force, which is caused by the asymmetric flow over these kinds of traditional slender body configurations with blunt nose at a high attack angle, induces the yawing or rolling deviation and the missiles will lose their predicted trajectory consequently. This study examines and diminishes the side-force induced by the inevitable asymmetric flow around this traditional slender body configuration with blunt nose at a high angle of attack (AoA = 50 deg). On one hand, the flow over a fixed blunt-nosed slender body model with strakes mounted at an axial position of x/D = 1.6–2.7 is investigated experimentally at α = 50 deg (D is the diameter of the model). On the other hand, the wingspan of the strakes is varied to investigate its effect on the leeward flow over the model. The Reynolds number is set at ReD = 1.54 × 105 based on D and incoming upstream velocity. The results verify that the formation of asymmetric vortices is hindered by the existence of strakes, and the strake-induced vortices develop symmetrically and contribute to the reduction in side-force of the model. In addition, the increase in strake wingspan reduces asymmetric characteristics of the vortex around the model and causes a significant decrease in side-force in each section measured. The strake with the 0.1D wingspan can reduce the sectional side-force to 25% of that in the condition without strakes.

Blunt-Nose Inviscid Airflows With Coupled Nonequilibrium Processes

2003 ◽  
Vol 40 (5) ◽  
pp. 796-809 ◽  
Author(s):  
J. GORDEN HALL ◽  
ALAN Q. ESCHENROEDER ◽  
PAUL V. MARRONE
Keyword(s):  
Nonequilibrium Processes ◽  
Blunt Nose
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