Stored Pressure Driven Cycle for Rocket Propulsion

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Solution Overview

Problem

Existing rocket propulsion systems face inefficiencies in sustaining propellant flow during main combustion, particularly in systems relying on turbopumps driven by gas generators or expander cycles, which can be complex and costly due to high-pressure propellant storage and handling.

Innovation Solution

A stored pressure driven cycle where a turbopump is driven by a pressurant stored in a pressure tank, allowing selective release to sustain propellant flow for extended combustion periods, reducing complexity and cost by using valves to regulate fluid flow and minimizing high-pressure tank sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If propellant is stored at high pressure in storage tanks to sustain main combustion without turbopump pressurization, then system complexity is reduced, but the weight and volume of high-pressure storage tanks increase significantly

Engineering Contradiction:
Improvesystem complexityVSAvoidweight of storage tanks
Core Design Contradiction:
Device complexityVSWeight of moving object

Solution Approach 1:

The system divides the pressurization function into two separate systems: (1) high-pressure storage tanks for oxidizer only, and (2) a turbopump system with gas generator for fuel pressurization. This segmentation allows the fuel tank to be lightweight while the oxidizer tank handles high pressure, optimizing the overall weight-complexity tradeoff.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gas generator serves multiple functions: it generates hot gas to drive the turbopump, provides pressurization for the fuel tank, and sustains combustion during main operation. This multi-functionality reduces the need for separate systems, lowering overall complexity while maintaining efficient propellant delivery.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If a turbopump with gas generator is used to pressurize propellant for main combustion, then propellant flow is sustained effectively, but device complexity and cost increase

Engineering Contradiction:
Improvepropellant flow sustainabilityVSAvoidturbopump system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system merges the pressurization function and the combustion sustenance function into a single integrated turbopump-gas generator system. The gas generator exhaust directly drives the turbine, which powers the pump, creating a unified system that reduces component count and overall complexity while maintaining effective propellant flow.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gas generator uses a portion of the propellant (fuel and oxidizer) to generate the energy needed to drive the turbopump itself. This self-service mechanism eliminates the need for external power sources or additional complex pressurization systems, as the system uses its own resources to sustain operation.

Inventive Principle:
Principle #25Self-service

3Weight of moving object

If propellant is stored at low pressure in storage tanks, then tank weight and cost are reduced, but additional pressurization systems are required to sustain main combustion

Engineering Contradiction:
Improveweight of storage tanksVSAvoidpressurization system complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The system dynamically adjusts propellant delivery by using the turbopump to actively pressurize and meter fuel and oxidizer flow rates according to combustion demands. This dynamic pressurization replaces static high-pressure storage, allowing lightweight tanks while maintaining precise control over propellant delivery through pump-driven flow regulation.

Inventive Principle:
Principle #15Dynamics

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

This approach efficiently sustains propellant flow for prolonged combustion phases while minimizing the penalties of high-pressure storage, reducing system complexity and costs, and allowing for lightweight, cost-effective design of fuel and oxidizer tanks.

Implementation Method 1

the pressurant being selectively released from the pressure tank to drive the turbopump

Methodology Applied
Scientific EffectExpansion: Pressure Gradient

Implementation Method 2

a turbine in communication with at least one pump, wherein the turbine is arranged to be driven by the pressurant expanding therefrom

Methodology Applied
Scientific EffectTurbine: Turbine

Implementation Method 3

Rocket engines are arranged to combust at least one propellant

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

the pump arranged to pressurize the propellant

Methodology Applied
Scientific EffectPressurization: Pressurisation

Data Source

PatentEP3004616B1Stored pressure driven cycle
Publication Date: 2019.11.13 AEROJET ROCKETDYNE INC
  • EP3004616B1 patent drawingFigure 1

AI summary

A propulsion system according to an exemplary aspect of the present disclosure includes, among other things, a pressurant selectively released from a pressure tank to drive a pump to sustain propellant flow for main combustion.