Composite Slosh Baffle Mounting for Cryogenic Tank Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Attaching slosh baffles to composite propellant tanks is challenging due to significant temperature fluctuations and differences in coefficients of thermal expansion between tank materials, which can cause structural issues and compromise the connection between tank components.
Innovation Solution
A composite tank design with slosh baffles made from a material with a different coefficient of thermal expansion than the tank wall, featuring a radial gap that accommodates temperature-induced size changes, allowing the baffles to move relative to the wall while maintaining load transfer over the entire operating temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If slosh baffles are attached directly to composite tank walls, then structural support and connection stability are improved, but thermal expansion mismatch causes structural compromise and connection failure
Solution Approach 1:
The attachment system is segmented into multiple components: the baffle itself, an attachment assembly with mounting brackets, and the tank wall interface. This segmentation allows each component to be optimized independently - the brackets can be made from materials with intermediate thermal expansion properties, isolating the metal baffle from direct contact with the composite wall and accommodating differential thermal movement while maintaining connection stability
Solution Approach 2:
Attachment assemblies with mounting brackets serve as intermediary elements between the metal slosh baffles and composite tank walls. These intermediaries are strategically designed with materials and geometries that accommodate thermal expansion mismatch, acting as a buffer zone that transfers loads while allowing for differential thermal movement without compromising the connection
2Force
If metal slosh baffles are used in composite tanks, then damping effectiveness is improved, but thermal expansion difference causes structural issues
Solution Approach 1:
The system is divided into functional segments: the metal baffle portion that contacts propellant for damping, the attachment brackets that interface with the composite wall, and the radial gap that accommodates thermal movement. This segmentation allows the metal baffle to maintain its damping effectiveness while the attachment system handles thermal expansion separately
Solution Approach 2:
The radial gap dimension is specifically designed as a variable parameter that changes with temperature. The gap size is calculated based on thermal expansion coefficients and operating temperature ranges, allowing the baffle to move radially as temperature changes while maintaining proper damping function throughout the temperature cycle
3Force
If rigid attachment is used for slosh baffles, then load transfer is improved, but thermal stress causes connection compromise
Solution Approach 1:
The attachment system transitions from a static rigid connection to a dynamic system that adapts to thermal conditions. The radial gap allows the baffle to move dynamically with temperature changes, and the attachment assemblies flex to accommodate thermal expansion, maintaining load transfer capability while relieving thermal stresses that would accumulate in a purely rigid connection
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 solution ensures stable attachment and load transfer of slosh baffles to composite tank walls across extreme temperature fluctuations, preventing structural compromise and maintaining effective propellant damping throughout the tank's operation.
Implementation Method 1
the slosh baffles and the composite wall can experience different size changes due to the difference in their coefficients of thermal expansion
Implementation Method 2
the slosh baffles interact with the propellant flow and transfer kinetic energy of the propellant to the tank wall
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3D
AI summary
A composite tank (100) for a reusable launch vehicle (101) comprises a composite wall (104), having a first coefficient of thermal expansion. The composite wall (104) comprises a first end (102), a second end (103), a central axis (106), which passes through the first end (102) and through the second end (103), and a cylindrical interior surface (105). The composite tank (100) also comprises slosh baffles (110), formed from a second material, having a second coefficient of thermal expansion that is different from the first coefficient of thermal expansion. Each of the slosh baffles (110) is attached to the cylindrical interior surface (105) of the composite wall (104). Each of the slosh baffles (110) is annular and is separated from the cylindrical interior surface (105) of the composite wall (104) by a radial gap (109), selected, in part, based on a difference between the first coefficient of thermal expansion and the second coefficient of thermal expansion. The radial gap (109) is configured to change responsive to changes in temperature of the composite tank (100).