scholarly journals Aerothermoelastic Load Calculation for Hypersonic Vehicles Based on Multiphysics Coupled Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Hao Chen ◽  
Min Xu ◽  
Zihua Qiu ◽  
Dan Xie ◽  
Yabin Wang

To fulfill the design objective of a structure and thermal protection system, accurate load environment prediction is very important, so we present a high-fidelity aerothermoelastic load calculation method based on a partitioned computational fluid dynamics/computational structural dynamics/computational thermal dynamics (CFD/CSD/CTD) coupling analysis. For the data transformation between the CFD/CSD/CTD systems, finite element interpolation (FEI) is explored, and a shape-preserving grid deformation strategy is achieved via radical basis functions (RBFs). Numerical results are presented for validation of the proposed CFD/CSD/CTD coupling analysis. First, a simply supported panel in hypersonic flow is investigated for results comparison of the proposed coupling method and previous work. Second, a hypersonic forebody is investigated to explore the aerothermoelastic effects while considering the feedback between deformation and aerodynamic heating. The results show that the CFD/CSD/CTD coupling method is accurate for analysis of aerothermoelasticity. In addition, considering the aerothermoelastic effect, the shear force and bending movement increase with time before 900s and decrease after 900s, and at 900s increased percentages of 5.7% and 4.1% are observed, respectively. Therefore, it is necessary to adopt high-fidelity CFD/CSD/CTD coupling in the design of a structure and thermal protection system for hypersonic vehicles.

1997 ◽  
Vol 34 (5) ◽  
pp. 577-583 ◽  
Author(s):  
G. E. Palmer ◽  
W. D. Henline ◽  
D. R. Olynick ◽  
F. S. Milos

Author(s):  
Jeswin Joseph ◽  
S. R. Shine

Very high thermal loads are expected in re-entry vehicles traveling at hypersonic Mach numbers due to severe aerodynamic heating. In the present study, numerical investigations are carried out to analyze the use of film cooling technology for a fully reusable and active thermal protection system of the re-entry vehicle. Simulations are done to examine the fundamental flow phenomenon and the performance of blunt body film cooling in hypersonic flows. Simulations are conducted for a blunt -nosed spacecraft flying at Mach numbers varying from 4 to 8 and 40 deg angle of attack. Film cooling holes are provided on the bottom of the blunt-nosed body. Standard values at an altitude of 30 km are used as in flow boundary conditions. The dependency of blowing ratios, stream-wise injection angle and inlet Mach number on the film cooling effectiveness are investigated. It is observed that the film cooling effectiveness reduces with increase in coolant injection angle. The film cooling performance is found to be decreasing with increase in Mach number. The results could provide useful inputs for optimization of an active thermal protection system of re-entry vehicles.


2019 ◽  
Vol 9 (24) ◽  
pp. 5541 ◽  
Author(s):  
Vinh Tung Le ◽  
Nam Seo Goo

A skin structure for thermal protection is one of the most interesting components that needs to be considered in the design of a hypersonic vehicle. The thermal protection structure, if a dense structure is used, is heavy and has a large heat conduction path. Thus, a lightweight, high strength structure is preferable. Currently, for designing a lightweight structure with high strength, natural materials are of great interest for achieving low density, high strength, and toughness. This paper presents bio-inspired lightweight structures that ensure high strength for a thermal protection system (TPS). A sinusoidal shape inspired by the microstructure of the dactyl club of Odontodactylus scyllarus, known as the peacock mantis shrimp, is presented with two different geometries, a unidirectionally corrugated core sandwich structure (UCS) and a bidirectionally corrugated core sandwich structure (BCS). Thermomechanical analysis of the two corrugated core structures is performed under simulated aerodynamic heating, and the total deflection and thermal stress are presented. The maximum deflection of the present sandwich structure throughout a mission flight was 1.74 mm for the UCS and 2.04 mm for the BCS. Compared with the dense structure used for the skin structure of the TPS, the bio-inspired corrugated core sandwich structures achieved about a 65% weight reduction, while the deflections still satisfied the limits for delaying the hypersonic boundary layer transition. Moreover, we first fabricated the BCS to test the thermomechanical behaviors under a thermal load. Finally, we examined the influence of the core thickness, face-sheet thickness, and emittance in the simulation model to identify appropriate structural parameters in the TPS optimization. The present corrugated core sandwich structures could be employed as a skin structure for metallic TPS panels instead of the honeycomb sandwich structure.


2012 ◽  
Vol 710 ◽  
pp. 594-599
Author(s):  
S. Hari Krishna ◽  
Ajay Kumar ◽  
P. Karthikeyan ◽  
M.P. Abilash ◽  
N. Narayanankutty ◽  
...  

Space vehicles that re-enter earth’s atmosphere require thermal protection system (TPS) to safeguard them from intense aerodynamic heating. Depending on the type of re-entry (lifting/ballistic), trajectory, duration of flight in atmospheric regime etc., the heat flux may vary from 40kW/m2to 180kW/m2. In our studies on metallic TPS (MTPS), corrugated core is joined to either side of the skins by brazing. The brazed joint is evaluated using both pulsed thermography (PT) and ultrasonic testing. PT images show clear visualization of joint and defects. Also it is faster and easier. Ultrasonic testing is done using pitch-catch and pulse-echo techniques, which shows many limitations. In literature, it is reported that for brazed joints using ultrasonic testing, defect location can be identified by faster decay pattern of multiple echoes (compared to that of good location). In case of PM 2000 panel, reversal of the patterns is observed. This new phenomenon is verified with the support of PT. It is also found that for inconel panel, the decay patterns are as reported in literature.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Łukasz Brodzik

Purpose Paper aims to present problem of aerodynamic heating of a metallic heat shield. The key elements of this construction are metallic layers of superalloy honeycomb, which significantly increase the structure’s resistance to impact. Paper describes the problem of influence of damage size on increase of thermal load. Design/methodology/approach Numerical analysis was performed in a non-commercial environment FreeFem++ using finite element method, and its results were compared with the results given in the literature. Findings In thermal protection system, a modification was used to delay increase in temperature on the underlying structure as well as to reduce its maximum value. Originality/value In the further part of the paper, selected insulation material was modified by adding additional conductive material.


2013 ◽  
Vol 753-755 ◽  
pp. 1467-1476
Author(s):  
Xiao Bo Peng

Nowadays, reusable launch vehicle (RLV) has become a research focus of the transportation system between ground and space and the space weapon system. RLV plays an important role in controlling the cost of space transportation and performing the orbital mission. Since RLV would suffer from the aerodynamic heating inevitably during reentry, the thermal protection system (TPS) is designed to prevent too much heat transmitting to the vehicle structure and maintain the vehicle structure below a specified temperature limit. Several studies were performed to develop an understanding of not only the thermal and structural analysis of ceramic tile thermal protection system on the space shuttle but also the controlling factors of TPS. The TPS is subjected to the reentry heating and pressure profile of the Access to Space vehicle, and the transient temperature distribution and the resultant thermal stresses in the system are computed. Comparisons between various studies based on different assumptions were examined. By comparing these results with more realistic ones, the differences are evaluated. Results suggest that the TPS analysis must be based on reasonable and realistic parameters. Thus, engineers have to keep in mind that all parameters should be chosen very carefully to achieve results that close to practical ones.


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