scholarly journals Optimization and Re-Design of Integrated Thermal Protection Systems Considering Thermo-Mechanical Performance

2021 ◽  
Vol 11 (15) ◽  
pp. 6916
Author(s):  
Qiuyi Xu ◽  
Shu Li ◽  
Yang Meng
Keyword(s):  
Thermal Insulation ◽  
Mechanical Performance ◽  
Thermal Protection ◽  
Elastic Strain Energy ◽  
Topological Optimization ◽  
Bottom Surface ◽  
Optimized Design ◽  
Buckling Mode ◽  
Load Bearing ◽  
Integrated Thermal Protection System

Integrated thermal protection system (ITPS) is regarded as one of the most promising thermal protection concepts with both thermal insulation and load-bearing capacities. However, the traditional layout of webs could inevitably lead to thermal short effects and high risk of buckling failure of the ITPS. A topological optimization method for the unit cell of the ITPS was established to minimize the equivalent thermal conductivity and elastic strain energy with the constraint of maintaining structural efficiency. The ITPS was re-designed consulting the optimized cell configuration. In order to control the buckling-mode shape and the associated buckling load of the ITPS, the new design was further optimized, subjected to the total weight of the initial design. Detailed finite element models were established to validate the structural responses. By contrast, the optimized design presents lower bottom surface temperature and better thermal buckling characteristics, performing a better balance between thermal insulation and load-bearing constraints.

Thermal and Thermomechanical Performances of Pyramidal Core Sandwich Panels Under Aerodynamic Heating

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Gongnan Xie ◽  
Ruiping Zhang ◽  
Oronzio Manca
Keyword(s):  
Sandwich Panel ◽  
Thermal Protection ◽  
Sandwich Panels ◽  
Core Structure ◽  
Heat Transfer Analysis ◽  
Aerodynamic Heating ◽  
Load Bearing ◽  
Sequential Coupling ◽  
Protection Property ◽  
Integrated Thermal Protection System

According to the particular aerodynamic heating loads which hypersonic aerospace aircrafts suffered from in-service environment, a lightweight integrated thermal protection system (ITPS) named pyramidal core sandwich panel is designed. This is considered not only as an insulation structure but also a load-bearing structure. Compared to traditional thermal protection systems (TPSs), the sandwich panel has simultaneous lightweight, load-bearing, and excellent thermal protection property. The finite-element heat transfer analysis for the pyramidal core sandwich structure is performed, and the distributions of temperature in the structure are presented. Then sequential coupling method is adopted to analyze the thermomechanical performance of the structure and presentations of field of stress and displacement under aerodynamic and thermal load are provided. A comparison between corrugated-core sandwich panels and pyramidal core sandwich panels from the perspectives of heat insulation, strength, and mass is carried out. The results indicate that the particular performance of pyramidal-core structure is superior to that of corrugated-core structure.

ZIRCONIA FIBERS AS A COMPONENT OF HIGH TEMPERATURE THERMAL INSULATION (review)

2021 ◽  
pp. 79-86
Author(s):  
V.G. Babashov ◽  
◽  
N.M. Varrik ◽  
Keyword(s):  
High Temperature ◽  
Thermal Insulation ◽  
Zirconium Oxide ◽  
Thermal Protection ◽  
Sol Gel ◽  
Precursor Solution ◽  
Technical Literature ◽  
Thermal Protection Systems ◽  
Insulation Materials ◽  
Protection Systems

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.

Preparation and Properties of Phase Change Thermal Insulation Materials

2018 ◽  
Vol 281 ◽  
pp. 131-136
Author(s):  
Shi Chao Zhang ◽  
Wei Wu ◽  
Yu Feng Chen ◽  
Liu Shi Tao ◽  
Kai Fang ◽  
...  
Keyword(s):  
Phase Change ◽  
Thermal Insulation ◽  
Calcium Silicate ◽  
Phase Change Materials ◽  
Performance Test ◽  
Thermal Protection ◽  
Insulation Material ◽  
Insulation Materials ◽  
Short Time ◽  
Change Material

With the increase of the speed of vehicle, the thermal protection system of its powerplant requires higher insulation materials. Phase change materials can absorb large amounts of heat in short time. So the introduction of phase change materials in thermal insulation materials can achieve efficient insulation in a limited space for a short time. In this paper, a new phase change thermal insulation material was prepared by pressure molding with microporous calcium silicate as matrix and Li2CO3 as phase change material. The morphology stability, exudation and heat insulation of the materials were tested. The results show that the porous structure of microporous calcium silicate has a good encapsulation when the phase transition of Li2CO3 is changed into liquid. And the material has no leakage during use. The thermal performance test also shows that the insulation performance of the material has obvious advantages in the short term application.

Thermal Force and Moment Determination of an Integrated Thermal Protection System

AIAA Journal ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Oscar A. Martinez ◽  
Anurag Sharma ◽  
Bhavani V. Sankar ◽  
Raphael T. Haftka ◽  
Max L. Blosser
Keyword(s):  
Thermal Protection ◽  
Thermal Protection System ◽  
Protection System ◽  
Integrated Thermal Protection System

Analysis of the Influence of Transient State of the Overhead Pipeline Placed in an Open-Air Space on the Accuracy of its Insulation Assessment Based on the Results of Outer Shell Thermovision Diagnostics

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Tadeusz Kruczek
Keyword(s):  
Thermal Insulation ◽  
Thermal Protection ◽  
Thermal State ◽  
Infrared Camera ◽  
Transient State ◽  
Weather Conditions ◽  
Heat Losses ◽  
Energy Accumulation ◽  
Measurement Results

Abstract The proper thermal diagnostics of pipeline insulation is an important problem. The heat losses from the pipelines depend distinctly on the quality of this insulation. Changes in weather conditions cause transient accumulation of energy in the pipeline insulation and may cause difficulties during evaluation of the quality of the pipeline thermal insulation. Generally, the goal of this investigation was to identify the scale of energy accumulation inside thermal insulation. This is important because during the calculation of heat losses from thermal pipelines on the basis of infrared camera temperature measurement results usually a steady thermal state inside the insulation is assumed. In order to determine the distributions of the temperature inside the insulation, the calculations of the temperature changes inside the pipeline insulation for real changeable meteorological conditions with the use of software ansys-fluent and others have been carried out. Both the heat transfer between the inner pipeline tube and outer pipeline shell and energy accumulation inside the pipeline elements were considered. For the pipeline insulation evaluation purpose, different coefficients for the analysis of energy accumulation scale were defined and used. The measurement results of the temperature of inner pipeline tube and outer pipeline shell gathered during the operation of the special experimental rig were used as input data for the aforementioned numerical simulations. In these calculations, they constituted the first (Dirichlet's) boundary condition. The conclusions resulting from this work are useful for specialists involved in the technical evaluation of the thermal protection features of pipelines.

Design and Performance Analysis of Mixed Flow Turbine Rotors With Extended Blade Chord

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Thomas Leonard ◽  
Stephen Spence ◽  
Dietmar Filsinger ◽  
Andre Starke
Keyword(s):  
Transient Response ◽  
Mechanical Performance ◽  
Cone Angle ◽  
Chord Length ◽  
Optimized Design ◽  
Blade Angle ◽  
Peak Efficiency ◽  
Mixed Flow ◽  
Blade Thickness ◽  
Turbine Rotors

Abstract Mixed flow turbines offer additional design freedom compared with conventional radial turbines. This is useful in the automotive turbocharger application to reduce rotor inertia, which can be very beneficial for the transient response of a highly boosted downsized passenger car powertrain. A previously published study from the authors analyzed a series of nine mixed flow turbine rotors with varying blade cone angle and inlet blade angle. This paper reports an extension of that study with two further mixed flow turbine rotors where the chord length of the rotor blade was extended. The aim of this work was to understand both the aerodynamic and mechanical impacts of varying the chord length, particularly for the turbocharger application where off-design performance and transient response are very important. The baseline mixed flow rotor for this study had a blade cone angle of 30 deg and an inlet blade angle of 30 deg. Two further variations were produced; one with the trailing edge (TE) extended in the downstream direction across the entire blade span. In the second variation, the chord was extended at the hub corner only, while the shroud corner of the TE remained unchanged, with the aim of achieving some aerodynamic improvement while meeting mechanical requirements. When the blade was extended at both the hub and shroud, the inertia and stress levels increased significantly and the blade eigenfrequencies reduced. There was a significant improvement in peak efficiency, but the mechanical performance was unfavourable. The improvement in peak efficiency was mainly due to better exhaust diffuser performance and, therefore, would not be realized in most turbocharger installations. The blade that was extended at only the hub corner incurred very little additional inertia, and the centrifugal stresses and blade eigenfrequencies were improved. Consequently, it was possible to reduce the blade thickness at the TE in order to achieve a more aerodynamically optimized design. In this case, the mechanical performance was acceptable and there were efficiency improvements of up to 1.1% points at off-design conditions, with no reduction in peak efficiency or maximum mass flowrate. Therefore, the blade that was extended only at the hub produced some improvement within acceptable mechanical limits. The flow field features were considered for the three rotor geometries to explain the changes in loss and efficiency across the operating range.

scholarly journals Numerical Simulation and Experimental Testing of Topologically Optimized PLA Cervical Implants Made by Additive Manufacturing Methodics

2018 ◽  
Vol 12 (2) ◽  
pp. 141-144
Author(s):  
Jozef Živčák ◽  
Radovan Hudák ◽  
Marek Schnitzer ◽  
Tomáš Kula
Keyword(s):  
Additive Manufacturing ◽  
Static Loading ◽  
Surgical Intervention ◽  
Experimental Testing ◽  
Axial Loading ◽  
Topological Optimization ◽  
Optimized Design ◽  
The Finite Element Method ◽  
3D Printed ◽  
Cervical Area

Abstract The article focuses on compressive axial loading experimental testing and simulations of topologically optimized design and additively manufactured cervical implants. The proposed platform design is based on anatomical and biomechanical requirements for application in the cervical area. Thanks to new ways of production, such as additive manufacturing, and new software possibilities in the field of structural analysis, which use the finite element method and analysis, it is possible to execute topological optimization of an implant in construction solution, which would be impossible to make by conventional methods. The contribution of this work lies in investigation of 3D printed PLA cervical implant usage in surgical intervention and creation of a numerical static loading modelling methodics and subsequent experimental confirmation of the modelling correctness.

scholarly journals Research on Thermal Insulation Performance of Lightweight Thermal Protection Materials for High Speed Aircraft under Different Boundary Conditions

2018 ◽  
Vol 179 ◽  
pp. 02001
Author(s):  
Feng Wang ◽  
Dafang Wu ◽  
Haoyuan Ren
Keyword(s):  
Boundary Conditions ◽  
Thermal Insulation ◽  
High Speed ◽  
Thermal Protection ◽  
Different Boundary Conditions ◽  
Flight Vehicles ◽  
Calculation Results ◽  
Different Temperatures ◽  
Insulation Performance

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.

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