Influence of angle of attack on a combined opposing jet and platelet transpiration cooling blunt nose in hypersonic vehicle

2020 ◽  
Vol 21 (9) ◽  
pp. 761-769 ◽  
Author(s):  
Bin-xian Shen ◽  
Hong-peng Liu ◽  
Wei-qiang Liu
Author(s):  
Zhang ZhunHyok ◽  
Won CholJin ◽  
Ri CholUk ◽  
Kim CholJin ◽  
Kim RyongSop

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.


2018 ◽  
Vol 141 (6) ◽  
Author(s):  
Qihang Yuan ◽  
Yankui Wang ◽  
Zhongyang Qi

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.


2021 ◽  
Vol 9 ◽  
Author(s):  
Shibin Luo ◽  
Zhichao Miao ◽  
Jian Liu ◽  
Jiawen Song ◽  
Wenxiong Xi ◽  
...  

As a promising and efficient active cooling method, double layer transpiration cooling is introduced into the design of the cooling system in the leading edge of a hypersonic vehicle. The physical model is built combined with hypersonic transpiration cooling, film cooling, heat conduction, porous media heat conduction and convection heat transfer. In addition, effects of different kinds of coolants are considered to reveal cooling mechanisms in different operation conditions. A comprehensive turbulence model validation and mesh independence study are provided. Flow characteristics caused by flow impingement, separation, transition and interaction with the cooling flows are displayed and analyzed in the work. When different kinds of coolants supplied at the same mass flow rate, the coolants with low densities, i.e., H2 and He, have the lowest peak temperature compared with the coolants with large densities, i.e., N2 and CO2. The coolants with low densities have a large ejecting velocity which provides large kinetic energy to penetrate deeply in the porous media. In addition, when the ejecting velocity is large enough, a recirculation is formed in front of the leading edge and pushes the high temperature region located in stagnation region away from the leading edge. However, when the coolants are ejected at the same velocity, the coolants with large densities exhibit better cooling performance.


2013 ◽  
Vol 823 ◽  
pp. 62-66
Author(s):  
Xin Min Wang ◽  
Peng Zhang ◽  
Cong Chao Yao

During the time that a hypersonic vehicle experiences the reentry segment, the environment changes dramatically. This paper analyzes all kinds of constraint conditions of the reentry process, then designs the reentry corridor in both the D-V plane and the H-V plane, and analyzes the influence of various factors on the reentry corridor according to that. Based on the constraint conditions, the reentry segment is divided into the initial descent phase, angle of attack recovery phase, overload hold phase and angle of attack transition phase. Meanwhile the rationality of the design is verified by simulation.


2019 ◽  
Vol 18 (2) ◽  
pp. 7-20 ◽  
Author(s):  
V. L. Balakin ◽  
M. M. Krikunov

Disturbed motion of a hypersonic vehicle in climb is analyzed. Deviations of atmospheric density from standard values and deviations of aerodynamic force coefficients from nominal values are taken as disturbances. Disturbed motion of a hypersonic vehicle with the optimum angle-of-attack schedule and nominal flight characteristics is modeled. Deviations of terminal conditions of disturbed motion from the target values of velocity, altitude and path inclination are determined. Using the method of Pontryagin’s maximum principle the problem of fuel mass minimum consumed in hypersonic acceleration climb is solved for disturbed motion. Optimal angle-of-attack schedules, optimal flight paths and finite values of the hypersonic vehicle’s mass are determined. Comparative analysis of optimal control programs and flight paths obtained for disturbed and undisturbed motion is carried out.


2012 ◽  
Vol 198-199 ◽  
pp. 207-211
Author(s):  
Yu Xiang Zhang ◽  
Jin Biao Xu ◽  
Fu Hou Xu ◽  
Hua Cheng Li

During the flight of the hypersonic Vehicle, the angle of attack will change with the flight attitude. At the same time, the aerodynamic forces from the surface of aircraft will also be changing. The pressure and friction force are the main causes of the aerodynamic heating, so the surface aerodynamic heating will change. By used the method of numerical calculation, the passage studied the influence the change the pressure and friction force on the distribution of heat flux in different angle of attack and the relationship between the change of the force of lift-drag and aerodynamic heating. The research suggested that the distribution of the heat flux had very good consistency with that of pressure and friction. The lift change was the dominant factors influence of pneumatic thermal change; the change of drag force affected only the speed of heat flux change.


Sign in / Sign up

Export Citation Format

Share Document