Features of the research of the efficiency of thermal protection of complex-profile surfaces streamlined by high-speed disperse flow

2018 ◽  
Author(s):  
Theodore E. Simos ◽  
Ruslan V. Fedorov ◽  
Vladislav N. Kovalnogov
2018 ◽  
Vol 172 ◽  
pp. 01007
Author(s):  
Harish Panjagala ◽  
E L N Rohit Madhukar ◽  
I Ravi Kiran

Due to increasing demand of High Speed Re-entry vehicles for Space activities within the world, a serious issue associated with the method of deceleration down a vehicle is by the intense heat generated because of development of stronger shocks at the nose. The price of thermal protection systems (TPS) to cut back the warmth generated by the return vehicles is extremely high. In this paper, the ultimate outcome is to cut back the aero heating which is achieved by introducing a spike at frontal region of the nose. Additionally, this spike avoids the deterioration and preserves the structural integrity of space vehicle over elevated temperatures. Further, four totally different geometries of tip specifically Blunt, Slender, Snap and Pan for the aerospike has been introduced and their impact on performance is evaluated and compared with the vehicle having TPS. Hence, usage of aerospike in return vehicles is the most successful and economical over different protection system.


2014 ◽  
Vol 4 (2) ◽  
pp. 021004 ◽  
Author(s):  
Dafang Wu ◽  
Anfeng Zhou ◽  
Liming Zheng ◽  
Bing Pan ◽  
Yuewu Wang

2019 ◽  
Author(s):  
Vladislav N. Kovalnogov ◽  
Ruslan V. Fedorov ◽  
Larisa V. Khakhaleva ◽  
Andrei V. Chukalin ◽  
Aleksandr N. Zolotov

2018 ◽  
Vol 179 ◽  
pp. 02001
Author(s):  
Feng Wang ◽  
Dafang Wu ◽  
Haoyuan Ren

The determination of thermal insulation performance of thermal protection materials or structures is an indispensable and important step in the safety design of high speed flight vehicles. To obtain the temperature difference of the radiating surface for plate specimens under three different boundary conditions in heat insulation experiments (the specimens were placed either vertically or horizontally with the radiating surface facing down or horizontally with the radiating surface facing up), three thermal test setups were established to test the thermal insulation performance of light-weight ceramic specimens at different temperatures. The results show that the radiating surface temperature was the highest when the specimen was placed horizontally with the radiating surface facing down, while it was the lowest when the specimen was placed horizontally with the radiating surface facing up.The numerical calculation results agreed very well with the experimental ones, confirming the credibility and accuracy of the experimental results. The different thermal insulation performances of the plate specimens obtained under three different boundary conditions will provide important guidance for designers in the design of thermal protection systems for large cabins of high speed flight vehicles.


2011 ◽  
Vol 105-107 ◽  
pp. 220-226 ◽  
Author(s):  
Yun Dong Sha ◽  
Zhi Jun Gao ◽  
Fei Xu

Thin-walled structures of future hypersonic flight vehicles will encounter complex loadings and exhibit obvious nonlinear responses. The thermal loads from high speed flow or engine jet flow can cause thermal buckling of thin-walled structures, such as Thermal Protection System (TPS). If the structures are loaded with intense acoustic loads simultaneously, large deflection nonlinear response, including snap-through, can be induced. Snap-through will give rise to large amplitude stress cycles and non-zero mean stress, which can lessen the fatigue life markedly. Starting from Hooker’s Law with thermal components, the large deflection governing equations of motion for simply-supported plate under thermo-acoustic loadings are derived. The partial differential equation (PDE) of motion which is difficult to solve is then transformed with Galerkin’s method to the system of ordinary differential equations (ODE) under modal coordinates. The displacement responses under different combinations of temperature increments and sound pressure levels are calculated by employing Runge-Kutta method. Typical thermo-acoustic responses are predicted: 1) random vibration around pre-buckled equilibrium position, 2) persistent snap-through between post-buckled positions, 3) intermittent snap-through, 4) vibration around one of the two post-buckled positions. By dividing the restoring force term in the equation into linear term and nonlinear one, the evolutions of each term are obtained to illustrate the mechanism of thermo-acoustic response and the contributions of each force, including shear force, thermal force and membrane force. Thus a further insight into thermo-acoustic response has been achieved.


Author(s):  
V.A. Tovstonog

In modern technology, gas dynamic facilities with a flow path of a high-temperature working fluid are widely used. Their effectiveness largely depends on the maximum achievable temperature, which is to a great extent determined by the heat resistance of structural materials and thermal protection systems of the most heat-stressed structural units. Most often, mass transfer thermal protection methods using the coolant of fuel components are used in such plants. However, in some gas dynamic facilities, such as high-speed ramjet engines, the use of such methods is only sufficient to maintain an acceptable temperature level for the elements of the flow path itself. As for the thermal protection of the enclosing structural elements which are adjacent to the path, it can be provided with either uncooled screens or heat-insulating linings. The study gives a comparative assessment of the temperature regime and characteristics of alternative types of heat shields


Author(s):  
Chen Xia ◽  
Guoping Huang ◽  
Jie Chen

The design and construction of a new test facility of micro turbo-machinery are presented for micro centrifugal compressors and radial turbines. The bed can be used for the full speed compressor test and the long duration hot turbine test. In order to adjust the testing condition rapidly, all the regulations of operating state are completed automatically by the control system. The test bed can be used for testing impeller performance with a series of diameter from 55 to 180 mm as a result of the modular design. A thermal protection system is designed to avoid the heat distortion caused by the high inlet temperature of turbine which may exceeds 1100K and provide a proper experimental environment for the electronic components. A photoelectric torque transducer with an accuracy of 1% is designed to measure the torque of a rigid shaft at a high speed over 120000rpm, and the maximum shaft torque is 7.7 N·m. The pressure and temperature are measured by pressure probes and thermocouples. The dynamic pressure signal of the centrifugal compressor is monitored by dynamic pressure sensors. The V-cone pressure-difference mass-flow meters are used for measuring mass-flow. The maximum rotating speed is 125000rpm, and the mass flow adjusted by the electric control valves varies from 0.1 to 1.0 kg/sec. The maximum inlet total temperature of the turbine is 1180K.


2013 ◽  
Vol 376 ◽  
pp. 317-322
Author(s):  
Jun Zhang ◽  
Rong Zhong Liu ◽  
Rui Guo ◽  
Xiao Dong Ma

Aero-heating problem severely affects the performance of terminal-sensitive projectile (TSP) when projected out of the carrier capsule by the gunpowder gas at a high speed. In this paper, based on the typical ballistic data and airflow physical parameters at deceleration and despinning trajectory, the aerodynamic thermal characteristics of a TSP was simulated by Fluent, and the transient temperature distributions were obtained under the different flying conditions. Finally, we got stagnation temperatures by the numerical simulations which were similar to those by the engineering evaluation, and demonstrate the effectiveness of the simulation method. The results are valuable to the research of thermal protection and infrared signature of TSP.


2010 ◽  
Vol 3 (1) ◽  
pp. 9-9
Author(s):  
Raffaele Savino

Improved interest in ultra-high-temperature ceramics (UHTCs) is being animating the scientific community. This emerging attention is driven by the demand of developing re-usable hot structures as thermal protection systems of aerospace vehicles, able to re-enter in planetary atmospheres at relatively high speed (order of 8-11 Km/s). In contrast to traditional blunt capsules or Shuttle-like vehicles, characterised by poor gliding capabilities and complex thermal protection systems, the future use of UHTCs opens new horizons for the development of spaceplanes with slender fuselage noses and sharp wing leading edges. Advanced aerodynamic configurations reduce the vehicles drag, enhance the vehicles performances, due to a larger manoeuvrability resulting in larger down range, cross range and abort windows, and reduce electromagnetic interferences and communications black-out. Analysis has shown that materials with temperature capability approaching 2000°C and above will be required for these space vehicles, but the state of the art Reinforced Carbon-Carbon (RCC) material, currently used on the Space Shuttle, have maximum use temperatures of approximately 1650°C. The articles collected in this issue provide state-of-art scientific advancements on the subject with particular attention to the potential technological applications. The papers specifically deal with research studies on monolithic ceramic materials, composed primarily of Zirconium and Hafnium Diborides with different additives. The activities are carried out at materials level, with furnace or arc-jet testing, or include developments of UHTC-based hot structures at sub-component level. In the latter case, ultra-high temperature ceramic prototype structures have been developed and tested with embedded structural health monitoring systems. I want to thank all the article contributors for their manuscripts. I hope they will be useful for future basic and applied researches on the subject.


Sign in / Sign up

Export Citation Format

Share Document