Dual-Liner Scramjet Testing Apparatus for High-Pressure Stability
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Solution Overview
Problem
Conventional Scramjet engine testing apparatuses face breakage due to high-pressure and high-temperature conditions, particularly in blow-down type high enthalpy wind tunnels, where the pressure difference between internal and external liners leads to structural failure and thermal expansion issues.
Innovation Solution
A testing apparatus design featuring a dual-liner configuration where the outer circumference of a second tubular liner overlaps with the inner circumference of a first tubular liner, with spacers maintaining distance, allowing for pressure equalization and sliding movement to mitigate pressure and thermal expansion stresses, using materials like nickel-chromium-based alloys and tantalum-zirconium-molybdenum alloys for durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single liner is used in the pipe to endure high temperature and pressure, then the structure is simple, but the liner breaks due to pressure difference and thermal expansion during extended testing
Solution Approach 1:
The single liner is divided into two separate liners (first liner and second liner) that can move independently relative to each other. This segmentation allows each liner to handle different aspects of the stress - the first liner primarily endures thermal expansion while the second liner manages pressure differential, thereby preventing breakage during extended testing periods of 30 seconds or longer
Solution Approach 2:
The two liners are designed to move dynamically relative to each other along the axial direction of the pipe. The liners are not rigidly fixed but can slide past each other within the pipe, allowing the system to adapt to changing pressure and temperature conditions during operation. This dynamic configuration prevents stress accumulation that would lead to breakage
2Duration of action of moving object
If the test time is extended to 30 seconds or longer in blow-down type high enthalpy wind tunnel, then more comprehensive testing is achieved, but the pressure difference causes liner breakage
Solution Approach 1:
By segmenting the liner into two movable parts, the system can maintain structural integrity throughout extended test periods. Each liner segment independently responds to pressure changes, preventing the cumulative stress that would cause breakage in a single rigid liner during long-duration testing
Solution Approach 2:
The space between the two liners acts as an intermediary chamber that allows pressure equalization. This intermediate space enables the liners to move and adjust to pressure differential changes over time, maintaining seal integrity and preventing breakage during extended operation
3Temperature
If the liner endures high temperature of 1800 K or above, then the Scramjet engine testing requirement is met, but thermal expansion causes liner breakage
Solution Approach 1:
The liners are designed with axial mobility to dynamically accommodate thermal expansion. As the liners heat up to 1800 K or above during Scramjet testing, they can expand and move along the pipe axis without generating excessive stress, thereby maintaining structural stability and preventing breakage
Solution Approach 2:
The system allows physical parameters (position, spacing) of the liners to change in response to temperature changes. The liners can adjust their axial positions and spacing as temperature varies during testing, accommodating thermal expansion and contraction cycles without compromising reliability
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 dual-liner configuration effectively reduces pressure differences and prevents breakage by allowing pressure equalization and accommodating thermal expansion, ensuring stable operation for extended periods in high-pressure and high-temperature environments.
Implementation Method 1
an outer circumference of a second liner is overlapped with an inner circumference of a rear end of the first liner
Implementation Method 2
the thermal expansion of the liner can also lead into breakage of the liner
Data Source
AI summary
A testing apparatus for Scramjet engine is capable of preventing breakage of liners in a high-pressure and high-temperature environment in which pressure is 10 Mpa or above and temperature is 1800 K or above. To this end, the testing apparatus for Scramjet engine includes a pipe that endures high-pressure environment, a first liner in a tubular shape, being provided within the pipe, and a second liner in a tubular shape, being provided within the pipe, in which an outer circumference of the second liner is overlapped with an inner circumference of a rear end of the first liner.