Monolithic Graphite Gas Distributor for Symmetric EP Propellant Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas distributors for electric propulsion systems are complex and expensive to manufacture, limiting their operating temperatures and power density due to material constraints, and struggle with achieving high azimuthal symmetry in propellant flow.
Innovation Solution
A low-cost, simple-to-manufacture gas distributor design fabricated from graphite or alternative conductive materials, featuring a single-piece annular structure with a triangular cross-section and circumferentially arranged holes, allowing high azimuthal and radial diffusion of propellant flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional multi-layer metallic gas distributors are used, then azimuthal symmetry of gas flow is achieved, but manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent combines multiple functional layers (gas distribution layers with azimuthal holes and radial diffuser layers) into a single monolithic graphite component. The gas distributor features an integrated structure where the upstream gas channel region with circumferential hollow region and downstream gas diffuser region with triangular cross-section are formed as one piece, eliminating the need for multiple welded metallic rings and reducing assembly complexity while maintaining azimuthal symmetry through circumferentially arranged holes at two radial positions.
Solution Approach 2:
The patent changes the material parameter from metallic alloys to graphite, which enables high-temperature operation and simplifies manufacturing. The graphite material allows for direct machining of the complex geometry including the triangular cross-section and circumferential hollow region, replacing the need for complex multi-layer metallic assemblies with welded joints.
2Temperature
If metallic gas distributors are used, then structural strength is sufficient, but operating temperature is limited to about 600°C
Solution Approach 1:
The patent changes the material parameter from metallic alloys to graphite, which has a significantly higher melting point and can operate at temperatures exceeding 600°C. The graphite gas distributor maintains structural integrity at high temperatures while providing the necessary mechanical strength for EP system operation, enabling higher power density operation.
Solution Approach 2:
The patent uses graphite as a non-metallic material that combines high-temperature resistance with adequate mechanical strength. The graphite material properties enable operation at temperatures where metallic materials would fail, while the monolithic structure provides the necessary structural support without requiring additional reinforcement layers.
3Temperature
If graphite material is used, then high temperature operation is enabled, but machining complexity increases
Solution Approach 1:
The patent combines multiple features (circumferential hollow region, radial diffuser channels, azimuthal holes at two radial positions) into a single monolithic graphite component that can be machined from a solid block. The integrated design eliminates the need for assembling multiple machined parts, reducing the overall machining complexity despite the intricate geometry required for high-temperature operation.
4Power
If conventional metallic gas distributors are used, then structural integrity is maintained, but power density is limited due to temperature constraints
Solution Approach 1:
The patent changes the material parameter from metallic alloys to graphite, which has a significantly higher maximum operating temperature. This material parameter change enables the anode to operate at higher temperatures, thereby increasing the power density of the EP system without compromising structural integrity. The graphite material maintains strength at temperatures where metallic materials would fail.
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
Enables operation at higher temperatures and power densities, reducing manufacturing costs by 80-90% and providing improved symmetry and thermal management, facilitating the use of alternate propellants.
Implementation Method 1
use of graphite may allow a target EP system to operate at an anode temperature of 600° C. or more above the state of practice while radiating a higher portion of thermal energy away from the EP system thanks to the higher emissivity of the graphite
Implementation Method 2
Gas distributors for Electric Propulsion (EP) systems (e.g., Hall effect thrusters, gridded ion thrusters) require delivery of (propellant) gas with a high degree of azimuthal symmetry
Data Source
AI summary
Systems and methods for a low cost and simple to manufacture gas distributor for use as an anode in an electric propulsion (EP) system are presented. According to one aspect, the gas distributor is a single integrated structure made of a single material, including graphite or steel. The gas distributor includes an annular shape with axial symmetry about a center axis. The gas distributor includes an upstream gas channel region and a downstream gas diffuser region. The gas channel region includes a circumferential hollow region, and two sets of axial holes arranged at respective radial positions. A radial cross section of the gas distributor includes an upstream opening corresponding to the hollow region of the gas channel region and a downstream triangular shape corresponding to the gas diffuser region. A radial extension of the triangular shape axially interferes with the two sets of axial holes.