Integrated design system for dynamic thermal protection system sizing

Abstract

In order to obtain a minimized weight design for a hypersonic vehicle, a design system that involves integrating aeroheating analysis with thermal protection system (TPS) sizing has been developed. The design system has the capability to analyse aeroheating and TPS thermal response and to provide an optimization capability to determine the minimum thickness of the TPS materials required to prevent the underlying structure from exceeding its operating temperature limit. Features of this system are the extended capability to analyse thermal response of metallic multi-layer TPS with non-grey insulation and the smart TPS for next generation or future TPS design. The application of the above design system to a model spacecraft is presented, showing good agreement with previously obtained results, and proving its reliability for future design use. The application of the extended capabilities also shows that the above design system has strong applicability to the following generations of TPS materials. and 'dynamic' TPS sizing [3,4]. Based on the concept of dynamic TPS sizing, Cowart and Olds [4] developed a tool for automated TPS design, in which the aeroheating was predicted by the fast engineering code MINIVER (MINIature VERsion aero-thermal analysis program) because dynamic TPS sizing calls for continuous updating of TPS parameters as the design process proceeds. Dynamic TPS sizing is regarded as the preferred method of the two cited above [3]. The design system developed in this paper is based on the concept of dynamic TPS sizing of various TPS models, such as metallic multi-layer TPS with non-grey insulation and smart TPS. TPS DESIGN AND SIZING SYSTEMThe present system structure is shown in Fig. 1. The ACAT provides the aerothermal environments required for the TPS design. The TPS-MDPT provides parameters of thermal protection materials and material mapping on the surface by the heat rate and temperature obtained from the ACAT. The TPS-TAT provides a means to calculate the transient in-depth conduction from the surface of the TPS. The OCT JAERO125

An approximate methodology to simulate combined conduction-radiation heat transfer for multi-layer insulator

“…In addition, BLS will be proportional to the temperature variation rate of the internal cold side. The analytical formulations of TLS and BLS are given as follows: P T LS = T 4 T OP L 1 T OP " T OP 8 > > > > > > > > > > < > > > > > > > > > > : @T hot @t @T hot @t < 0; @T cold @t < 0 @T hot @t + 2 @T cold @t @T hot @t < 0; @T cold @t > 0 1 @T hot @t = 0; @T cold @t < 0 2 @T hot @t = 0; @T cold @t > 0 (13)…”

“…E ective thermal conductivity approximation is inherently simple and does not require radiation heat transfer equation. This approach is popular, especially for researches in the eld of design or sizing of the high-temperature insulators [3,4]. For example, an ordinary equation is proposed for the radiative thermal conductivity of space shuttle tiles [5].…”

Axiomatic design of a reflective multilayer high-temperature insulator

“…As illustrated in equation (1), conduction and radiation could be considered separately in the heat transfer equation. 15 …”

“…This mechanism has also been considered in sizing of a tile insulator by imposing the hot side BC. 15 Thermal emissivity of the hot side surface is the associated DP with the energy excretion requirement.…”