Transpiration Cooling Thermal Protection Test System for Vaporization Control

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Solution Overview

Problem

Existing transpiration cooling thermal protection materials for hypersonic vehicles face challenges in maintaining both high permeability and strength, leading to liquid boiling and vaporization in the chamber, which increases internal pressure and temperature, potentially damaging the thermal protection material.

Innovation Solution

A transpiration cooling thermal protection test system that adjusts the opening and closing of a steam solenoid valve based on feedback from an armored thermocouple to maintain constant temperature and pressure, using a high-pressure nitrogen gas source, pressure sensors, and a porous thermal protection material to stabilize the liquid in the chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the permeability of the thermal protection material is increased to improve cooling efficiency, then the cooling effect is enhanced, but the material density decreases and strength is reduced

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmaterial strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent uses porous thermal protection materials with controlled pore structures to achieve both high permeability for cooling and sufficient strength for structural integrity. The porous structure allows liquid coolant to penetrate and evaporate effectively while maintaining mechanical strength through optimized pore size and distribution.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent employs composite material structures combining different materials with complementary properties - one material providing structural strength and another providing permeability for transpiration cooling. This composite approach resolves the contradiction between strength and permeability by integrating both functions in a single thermal protection system.

Inventive Principle:
Principle #40Composite materials

2Strength

If the permeability is kept small to ensure material strength, then the strength is maintained, but the liquid stays in the chamber longer causing boiling and vaporization under high temperature

Engineering Contradiction:
Improvematerial strengthVSAvoidoperational stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent implements feedback control by monitoring temperature and pressure conditions in the chamber and adjusting the transpiration cooling rate accordingly. When temperature or pressure exceeds safe thresholds, the system increases coolant flow or activates pressure relief mechanisms to prevent liquid boiling and vaporization, ensuring continuous safe operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses dynamic adjustment of cooling parameters rather than static fixed-rate cooling. The transpiration cooling system can adapt its cooling rate in real-time based on operational conditions, increasing cooling when temperatures rise and reducing it when conditions are stable, thereby preventing vaporization while maintaining material strength.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the liquid in the chamber operates without temperature and pressure control, then the system is simpler, but the liquid boils and vaporizes increasing internal pressure and temperature that can damage the material

Engineering Contradiction:
Improvesystem complexityVSAvoidthermal damage risk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces intermediary control components such as pressure relief valves, temperature sensors, and flow control mechanisms that mediate between the cooling liquid and the thermal protection material. These intermediaries monitor and regulate temperature and pressure, preventing harmful vaporization while maintaining relatively simple overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent designs the thermal protection system to self-regulate through inherent physical mechanisms - the porous material itself provides capillary action to distribute coolant, and phase change of the coolant (evaporation) naturally provides cooling when temperature rises. This self-service approach reduces the need for complex external control systems while preventing thermal damage.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system ensures stable operation of the liquid in the chamber, preventing damage to the thermal protection material by vaporization and pressure increase, thereby prolonging the thermal protection time and maintaining effective cooling under extreme temperatures.

Implementation Method 1

the liquid in the high-pressure liquid tank 4 pressurized by the high-pressure nitrogen gas source 1 enters the test body 6 through a pipeline via the flow meter 5, and penetrates into an outer surface of the porous thermal protection material 62

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the liquid in the chamber operates under conditions of the constant temperature and the constant pressure, and hence the problem of the vaporization of the cooling liquid in the test chamber is solved

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

The present invention adopts a manner of transpiration cooling thermal protection

Methodology Applied
Scientific EffectTranspiration cooling: Transpiration

Implementation Method 4

the liquid in the high-pressure liquid tank 4 pressurized by the high-pressure nitrogen gas source 1 enters the test body 6 through a pipeline

Methodology Applied
Scientific EffectGas pressurization: Pressurisation

Implementation Method 5

adjusts the opening and closing of a steam solenoid valve at a test chamber according to a feedback signal of an armored thermocouple which measures a temperature of the liquid in the test chamber

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 6

adjusts the opening and closing of a steam solenoid valve at a test chamber according to a feedback signal of an armored thermocouple

Methodology Applied
Scientific EffectFeedback control: Feedback

Implementation Method 7

A gas flow heated by an arc heater passes through the throat channel and nozzle assembly 11

Methodology Applied
Scientific EffectArc heating: Electric Arc

Implementation Method 8

A gas flow heated by an arc heater passes through the throat channel and nozzle assembly 11, and flushes the porous thermal protection material 62 in the flow channel downstream of the nozzle

Methodology Applied
Scientific EffectDe Laval nozzle effect: De Laval Nozzle

Data Source

PatentEP4636393A1Transpiration cooling-based thermal protection test system
Publication Date: 2025.10.22 CHINA ACAD OF AEROSPACE AERODYNAMICS
  • EP4636393A1 patent drawingFigure 1~2
  • EP4636393A1 patent drawingFigure 3
  • EP4636393A1 patent drawing

AI summary

A transpiration cooling-based thermal protection test system. According to the system, high-pressure nitrogen gas is injected into a high-pressure liquid tank (4) from the upper part, to force a liquid (water or oil) to flow to a test cavity (61) along a pipeline; a porous thermal protection material (62) is sealingly mounted on the outer surface of the test cavity (61); and the high-pressure liquid in the test cavity (61) permeates to the outer surface of the porous thermal protection material (62) to resist the scouring of hypersonic high-temperature incoming flow, thereby achieving the purpose of protecting the porous thermal protection material (62). Pressure and temperature measurement devices are additionally provided on the test cavity (61), and a steam electromagnetic valve (9) mounted on the test cavity (61) is controlled by taking the temperature as a feedback signal, so as to discharge a high-temperature and high-pressure gas-liquid mixture in the test cavity (61), thereby avoiding damage of the high-temperature and high-pressure gas-liquid mixture in the test cavity (61) to the porous thermal protection material (62), and achieving the purpose of long-time operation of a transpiration cooling-based thermal protection test.