Jet Pump Nozzle for Subsonic and Supersonic Propellant Flow
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Solution Overview
Problem
Jet pumps face challenges in operating effectively across both subcritical and supercritical pressure relationships, as existing nozzles either decelerate or fail to efficiently accelerate propellants, limiting their application range.
Innovation Solution
A jet nozzle design with a convergent inlet and a divergent outlet portion, where the opening angle of the inner wall allows propellants to be either released or guided based on speed, enabling operation across a wide pressure range without deceleration at subsonic speeds and further acceleration at supersonic speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a Laval nozzle with divergent outlet portion is used to accelerate propellant at supercritical pressure relationships, then the propellant is further accelerated to supersonic speed, but the propellant flows at subsonic speed is decelerated by the divergent portion acting as a diffusor
Solution Approach 1:
The nozzle geometry is designed to dynamically adapt its function based on flow conditions. The divergent outlet portion automatically switches between acting as a nozzle (for supersonic flow) and a diffusor (for subsonic flow) based on the pressure relationship, eliminating the need for separate nozzle designs for different operating conditions.
Solution Approach 2:
The opening angle of the divergent outlet portion is specifically optimized to change the flow behavior based on Mach number. By carefully selecting the opening angle parameters, the nozzle achieves optimal performance across both subcritical and supercritical pressure relationships, with the flow regime determining whether the divergent portion accelerates or decelerates the propellant.
2Adaptability or versatility
If a convergent nozzle is used for subcritical pressure relationships, then the propellant is accelerated efficiently, but the nozzle cannot further accelerate propellant to supersonic speed
Solution Approach 1:
The invention merges the functions of a convergent nozzle and a Laval nozzle into a single integrated nozzle design. The convergent inlet portion and divergent outlet portion work together to provide both subsonic acceleration and supersonic acceleration capabilities, allowing the same nozzle to serve multiple functions across different operating conditions.
3Reliability
If separate nozzles are used for subcritical and supercritical pressure relationships, then optimal performance is achieved for each condition, but the device complexity increases
Solution Approach 1:
The nozzle is designed as a universal component that performs multiple functions: it acts as a convergent nozzle for subcritical pressure relationships and as a Laval nozzle for supercritical pressure relationships. This multi-functionality eliminates the need for separate nozzle designs, reducing device complexity while maintaining operational efficiency across different pressure conditions.
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 seamless operation across subcritical and supercritical pressure conditions, preventing pressure shocks and expanding the jet pump's application range by maintaining efficient suction action and propellant acceleration.
Implementation Method 1
the convergent inlet portion accelerates a propellant which flows through the convergent inlet portion
Implementation Method 2
If the propellant after flowing through the inlet portion and the acceleration then continues to have subsonic speed
Implementation Method 3
a convergent/divergent nozzle, a so-called Laval nozzle, is used in order to further accelerate the propellant which has been accelerated to the speed of sound in the convergent portion of the Laval nozzle
Implementation Method 4
the propellant is further accelerated by the divergent inner space of the outlet portion
Implementation Method 5
Jet pumps use a fluid jet comprising a propellant in order to draw in and accelerate a suction medium. The suction action is brought about by the propellant flowing past the suction medium, wherein the suction medium is also carried by the propellant when the flow speed of the propellant is sufficiently high
Data Source
AI summary
A jet pump comprising a jet nozzle for accelerating a propellant. The jet nozzle has a convergent inlet part and an outlet part connected to the convergent inlet part. The outlet comprises an inner wall diverging at an opening angle. The opening angle is designed such that a propellant flowing through the outlet part at subsonic speed is detached from the inner wall and a propellant flowing through the outlet part at supersonic speed is guided by the inner wall. An automatic, cost-effective and simple changeover of the jet pump to different pressure ratios is hence provided.