Glide trajectory optimization for hypersonic vehicles via dynamic pressure control

2019 ◽  
Vol 164 ◽  
pp. 376-386 ◽  
Author(s):  
Hongyu Zhou ◽  
Xiaogang Wang ◽  
Naigang Cui
1998 ◽  
Vol 191 (1-2) ◽  
pp. 225-233 ◽  
Author(s):  
T. Sawada ◽  
K. Takemura ◽  
K. Shigematsu ◽  
S. Yoda ◽  
K. Kawasaki

Author(s):  
Tiago Cavalcanti Rolim ◽  
Sheila Cristina Cintra ◽  
Marcela Marques da Cruz Pellegrini

This work presents a computational tool for preliminary analysis of hypersonic vehicles, based on local surface inclination methods: the HipeX. This program was developed for reading standard triangulation language (STL) geometry files and calculating pressure coefficient and temperature distributions over vehicle’s surface using the Newtonian, modified Newtonian or tangent-wedge methods. Validations were made with a cylinder and a sphere, where only the Newtonian method was applied, and with experimental data from Apollo capsule at Mach 10, where the Newtonian and the modified Newtonian methods were applied. These validations presented the code capability to read geometries as well as to estimate aerodynamic force coefficients. A preliminary application was to predict the aerodynamic force coefficients of a generic hypersonic vehicle over constant dynamic pressure trajectories of 23,940, 60,000 and 95,760 N/m2 with zero angle of attack. With a fixed dynamic pressure of 60,000 N/m2, this vehicle was tested over several Mach numbers and with angle of attack variation from -10 to 10 deg. Zero angle of attack investigation showed minor changes on the force coefficients with altitude, while the variation of angle of attack produced more pronounced variations on these parameters. Maximum flow temperatures over vehicle’s surface were estimated ranging from 850 to 5,315 K.


Author(s):  
Cong Li ◽  
Yina Yao ◽  
Zhenxiang Tao ◽  
Rui Yang

To analyze the fire behavior in the dynamic pressure environment, a series of n-heptane pool fire experiments were conducted in an 8.11m × 4.16m × 1.67m simulated aircraft cargo compartment. The compartment is capable of mimicking flight environment from taking off to landing of the aircraft according to the standards of Federal Aviation Administration (FAA) by a pressure control system. Pool fires with 30cm diameter were tested under the dynamic pressure from 101kPa to 45kPa with various depressurization rates of 10kPa/min, 15kPa/min, 20kPa/min and 25kPa/min. Fire behavior such as burning rate, oscillation frequency and flame temperature were analyzed. The results revealed that the dynamic pressure influences the burning rate not only during the depressurization stage but also after depressurization. The oscillation frequency increases with the pressure decrease but has no relationship with depressurization rate. The flame temperature at different heights shows various tendencies with pressure.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chun-Mei Yu ◽  
Dang-Jun Zhao ◽  
Ye Yang

A novel sequential convex (SCvx) optimization scheme via the Chebyshev pseudospectral method is proposed for efficiently solving the hypersonic reentry trajectory optimization problem which is highly constrained by heat flux, dynamic pressure, normal load, and multiple no-fly zones. The Chebyshev-Gauss Legend (CGL) node points are used to transcribe the original dynamic constraint into algebraic equality constraint; therefore, a nonlinear programming (NLP) problem is concave and time-consuming to be solved. The iterative linearization and convexification techniques are proposed to convert the concave constraints into convex constraints; therefore, a sequential convex programming problem can be efficiently solved by convex algorithms. Numerical results and a comparison study reveal that the proposed method is efficient and effective to solve the problem of reentry trajectory optimization with multiple constraints.


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