Aircraft Nozzle Internal Flow Passage for Thermal Stress Reduction
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Solution Overview
Problem
Modern aircraft propulsion systems face premature degradation of components due to high gas temperatures, particularly in the core nozzle system exposed to engine combustion products, necessitating an improved nozzle design that can accommodate increasing temperatures.
Innovation Solution
The design incorporates a nozzle assembly with a fixedly connected nozzle panel and fairing, featuring an internal flow passage that extends axially to a radially configured outlet orifice, which includes a fluid source for cooling and sealing, and is strategically positioned to direct airflow and reduce thermal stress on the pylon structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If gas temperatures within the gas turbine engine are increased to improve efficiency and thrust, then engine performance is improved, but component durability deteriorates due to premature degradation from high temperatures
Solution Approach 1:
A fluid passage system is introduced as an intermediary between the hot combustion gases and the nozzle components. This passage delivers cooling fluid (air) to the nozzle panel and fairing, acting as a thermal mediator that protects these components from direct exposure to high temperatures while allowing the engine to operate at higher temperatures for improved thrust
Solution Approach 2:
The harmful thermal energy is extracted from the nozzle components through the fluid passage system. Cooling fluid is circulated through passages in the nozzle panel and fairing, absorbing heat and carrying it away from these components, thereby extracting the thermal stress that would otherwise cause premature degradation
2Reliability
If cooling fluid is circulated through the internal flow passage to cool nozzle components, then thermal stress on components is reduced, but device complexity increases due to additional fluid passages and outlets
Solution Approach 1:
The fluid passage system serves multiple functions simultaneously: it cools the nozzle panel, cools the fairing, and directs outlet air to seal between the fairing and pylon structure. This multi-functionality reduces the need for separate cooling systems for each component, thereby limiting the increase in device complexity while achieving comprehensive thermal protection
Solution Approach 2:
The cooling passages for the nozzle panel and fairing are merged into a unified fluid delivery system. The same fluid source supplies cooling fluid to both components through interconnected passages, and the outlet air from these passages is combined to perform both cooling and sealing functions, reducing overall system complexity
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 configuration enhances the durability of nozzle components by providing effective cooling and reducing thermal stress, thereby extending the lifespan of the nozzle system and maintaining efficiency even under severe operating conditions.
Implementation Method 1
The internal flow passage extends radially between the nozzle panel and the nozzle fairing and is configured to receive air from a fluid source
Implementation Method 2
providing effective cooling and reducing thermal stress
Data Source
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AI summary
An assembly is provided for an aircraft propulsion system. This assembly includes a nozzle (50) extending axially along and circumferentially about an axial centerline (30). The nozzle includes a nozzle panel (76) and a nozzle fairing (78) fixedly connected to the nozzle panel at an axial end (74) of the nozzle. The nozzle is configured with an internal flow passage (84) radially between the nozzle panel and the nozzle fairing. The internal flow passage extends axially within the nozzle to an outlet (90) between the nozzle panel and the nozzle fairing at the axial end of the nozzle.