RBCC RDRE Bypass-Air Cooling for Thermal and Throat Control

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Solution Overview

Problem

Combining a rotating detonation rocket engine (RDRE) with an airbreathing jet engine in a rocket-based combined cycle (RBCC) propulsion system presents thermal management challenges due to hot jet engine exhaust raising the RDRE temperature above allowable operating levels, and affects the performance of the jet engine by modifying its throat area.

Innovation Solution

Utilizing bypassed air from the jet engine for cooling the RDRE, including film cooling, circulating jet engine fuel through the RDRE casing, and controlling the RDRE's geometry and position to manage thermal loads and optimize jet engine performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the RDRE is located downstream of the jet engine in the exhaust flow path, then the RBCC propulsion system can operate in multiple flight regimes using a single propulsion system, but the hot jet engine exhaust raises the temperature of the RDRE above allowable operating temperatures

Engineering Contradiction:

Improvemulti-flight regime operationVSAvoidRDRE temperature

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent extracts the RDRE from the hot exhaust flow path by positioning it in a bypass flow path that receives cooling air from the jet engine. This separation removes the RDRE from the harmful thermal environment while preserving the integrated propulsion system's ability to operate across multiple flight regimes.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces cooling air as an intermediary substance between the hot exhaust and the RDRE. This cooling air, bypassed from the jet engine, acts as a thermal mediator that protects the RDRE from overheating while allowing the system to maintain its multi-regime operational capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the RDRE is located downstream of the jet engine, then the propulsion system integrates rocket and airbreathing functions, but the RDRE modifies the throat area at the jet engine exhaust nozzle affecting jet engine performance

Engineering Contradiction:

Improveintegrated propulsion functionVSAvoidjet engine thrust

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the exhaust flow path into two separate channels: a main exhaust path for the jet engine and a bypass path for the RDRE. This segmentation allows the jet engine to operate with its original throat area and performance characteristics while the RDRE receives cooled air through the bypass path, eliminating the negative interaction between the two engine types.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bypass duct system acts as an intermediary structure that diverts a portion of the exhaust flow away from the RDRE. This intermediary flow path prevents the RDRE from interfering with the jet engine's throat area and exhaust dynamics, thereby preserving jet engine thrust while maintaining integrated propulsion functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If bypassed air is used for film cooling the RDRE, then the RDRE is cooled to allowable operating temperatures, but additional cooling infrastructure is required

Engineering Contradiction:

ImproveRDRE temperatureVSAvoidcooling system infrastructure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent implements a self-service cooling system where the jet engine's own exhaust air is used to cool the RDRE. The bypassed air, which would otherwise be wasted, is redirected through the RDRE casing and annular spaces to provide film cooling. This eliminates the need for external cooling sources or additional complex cooling infrastructure.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent recovers the bypassed air that would normally be discarded from the jet engine exhaust. Instead of allowing this air to be wasted, it is redirected through the RDRE for cooling purposes. This recovery approach provides effective cooling while minimizing additional infrastructure requirements by utilizing already-present flow resources.

Inventive Principle:

Principle #34Discarding and recovering

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

Effectively cools the RDRE to allowable operating temperatures and maintains jet engine performance by using bypassed air for film cooling and modifying the RDRE's geometry, thereby ensuring efficient operation across multiple flight regimes.

Implementation Method 1

In one embodiment, we use bypassed air from the jet engine for film cooling the RDRE

Methodology Applied

Scientific EffectFilm cooling: Convection

Implementation Method 2

In another embodiment, we circulate the jet engine fuel through the RDRE casing and/or supports for the RDRE to cool the RDRE

Methodology Applied

Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentUS12571361B2Thermal management for ramjet-RDRE configuration of RBCC

Publication Date: 2026.03.10 VENUS AEROSPACE CORP

AI summary

Disclosed is an aircraft having a rocket-based combined cycle (RBCC) propulsion system including a rotating detonation rocket engine (RDRE) and an airbreathing jet engine. The RDRE is located within a throat area of the jet engine and is configured to be cooled by air bypassed from upstream of the jet engine.