Rocket Engine Propellant Feed Circuit Segmentation

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Solution Overview

Problem

Current rocket engine propulsion systems face limitations in achieving high pressures and specific impulse due to energy constraints in expander cycle engines and the need for large, heavy tanks for pressurization, which restrict the mixing ratio control and overall efficiency.

Innovation Solution

A device comprising a first propellant supply circuit with a turbopump and heat exchanger to actuate the turbine, and a second propellant supply circuit with an adjustable inlet valve for pressurization and flow rate control, allowing for efficient propellant mixing and reduced system size, using a pressurized gas to maintain high pressures and prevent cavitation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If an expander cycle engine is used to power the turbopump, then the propellant can be heated and the turbine can be actuated, but the energy available to power the turbine is limited by the heat exchanger capacity

Engineering Contradiction:
Improveturbine powerVSAvoidheat exchanger capacity
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

The propellant supply system is divided into two independent circuits: a first circuit using an expander cycle to power the turbopump, and a second circuit using pressurized storage to supply the propulsion chamber directly. This segmentation allows each circuit to be optimized for its specific function without energy transfer limitations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A pressurized storage tank acts as an intermediary between the propellant supply and the propulsion chamber. The tank receives pressurized propellant from a separate pressurization system and delivers it to the chamber, decoupling the energy requirements of the turbopump from the propellant delivery requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If the length and mass of the propulsion chamber are increased to overcome energy limitations, then more thermal flow can be extracted, but the overall system mass increases

Engineering Contradiction:
Improvethermal flow extractionVSAvoidpropulsion chamber mass
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The energy extraction function is separated from the propulsion chamber. Instead of extracting thermal flow from the chamber to power the turbine, the system uses a dedicated pressurization circuit that delivers pressurized propellant directly to the chamber, eliminating the need for large-scale thermal extraction.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stress or pressure

If turbopumps are used to supply both propellants, then high pressures can be achieved, but the system complexity and size increase

Engineering Contradiction:
Improvepropulsion chamber pressureVSAvoidsupply system complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The dual-propellant supply system is segmented into two different architectures: the first propellant uses a turbopump for pressurization, while the second propellant uses a pressurized storage tank with an adjustable valve. This segmentation reduces overall system complexity by avoiding the need for two identical turbopump systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different pressurization methods are applied to different propellants based on their specific requirements. The first propellant receives active turbopump pressurization, while the second propellant uses passive pressurized storage, optimizing each circuit for its particular function.

Inventive Principle:
Principle #3Local quality

4Ease of operation

If an adjustable valve is added to control the mixing ratio of propellants, then propellant ratio control is improved, but the device complexity increases

Engineering Contradiction:
Improvemixing ratio controlVSAvoidvalve arrangement complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The pressurized storage tank acts as an intermediary that enables simple flow rate control. By regulating the pressure and flow from the second tank through an adjustable valve, the mixing ratio can be controlled without complex turbine control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enhances the control of propellant mixing ratios, reduces the overall size and mass of the rocket engine, and maintains high performance and specific impulse, while avoiding cavitation and energy limitations, resulting in a more compact and efficient propulsion system.

Implementation Method 1

a heat exchanger configured to heat the first propellant with heat generated by the propulsion chamber to actuate the turbine of the turbopump

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

by expansion of the first propellant after its heating

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

at least one turbine mechanically coupled to said pump, said first supply circuit connecting an outlet of the pump with an inlet of the turbine

Methodology Applied
Scientific EffectTurbine expansion: Turbine

Implementation Method 4

at least one pump for pumping the first propellant

Methodology Applied
Scientific EffectPumping: Pump

Data Source

PatentEP2917547B1Method and device for powering a rocket motor
Publication Date: 2018.01.03 ARIANEGRP SAS
  • EP2917547B1 patent drawingFigure 1
  • EP2917547B1 patent drawingFigure 2

AI summary

The invention relates to a feed device for feeding a thrust chamber (10) of a rocket engine (100) with first and second propellants. According to the invention, a first feed circuit (16) of the thrust chamber (10) comprises a turbopump (22) having at least one pump (22a) for pumping the first propellant from a first tank (12), and a turbine (22b) mechanically coupled to said pump (22a). The first feed circuit connects an outlet of the pump to an inlet of the turbine via a heat exchanger (24) configured to heat the first propellant with heat generated by the thrust chamber, in order to actuate the turbine. According to the invention, a second feed circuit (18) is configured to feed the thrust chamber with second propellant from a second tank (14) that is configured to be pressurized. The invention also provides a method of feeding a rocket engine thrust chamber with first and second propellants.