Rotodynamic Fuel Pump Angular Inlet-Outlet Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art fuel pumps for aircraft engine fuel systems face performance issues under depressed inlet conditions due to fuel recirculation, which negatively affects delivery pressure regulation.
Innovation Solution
A rotodynamic fuel pump system that varies the angular relationship between the inlet and outlet to control delivery pressure by pivoting parts of the pump housing relative to each other, using either a passive or active pressure regulating mechanism, in response to pressure setpoints to maintain optimal fuel delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If fuel recirculation is used to regulate delivery pressure, then pressure regulation is achieved, but pump operational performance deteriorates under depressed inlet conditions
Solution Approach 1:
The patent extracts the harmful recirculation flow path by providing a separate pressure regulation mechanism that does not require recirculating fuel to the inlet. The outlet port is selectively communicable with the discharge passage through a pressure regulator, allowing pressure control without creating a recirculation loop that would degrade pump performance under depressed inlet conditions.
Solution Approach 2:
The patent introduces an intermediary pressure regulator component positioned at the outlet that mediates between the pump discharge and the fuel system. This regulator controls delivery pressure by providing a controlled discharge path without requiring fuel to return to the inlet, thus avoiding the performance deterioration caused by direct recirculation.
2Stress or pressure
If recirculation arrangement is implemented, then delivery pressure can be regulated, but fuel delivery efficiency decreases
Solution Approach 1:
The harmful recirculation path is extracted and replaced with a dedicated pressure regulation path. The outlet port can be selectively communicable with the discharge passage through a pressure regulator, allowing pressure control without creating a recirculation loop that would reduce fuel delivery efficiency.
Solution Approach 2:
The patent implements a dynamic pressure regulation system where the outlet port is selectively communicable with either the fuel system or the discharge passage through a pressure regulator. This dynamic switching allows the system to maintain high fuel delivery efficiency while regulating pressure as needed, rather than continuously recirculating fuel.
3Stress or pressure
If pressure regulator recirculates fuel to inlet, then delivery pressure is controlled, but pump performance under depressed inlet conditions is negatively affected
Solution Approach 1:
The patent extracts the recirculation function from the pressure control mechanism. The outlet port is selectively communicable with the discharge passage through a pressure regulator, providing pressure control without recirculating fuel to the inlet, thereby eliminating the negative effect on pump performance under depressed inlet conditions.
Solution Approach 2:
The patent segments the pressure regulation function from the fuel delivery path. By providing a separate outlet port that can be selectively communicable with the discharge passage through a pressure regulator, the system achieves pressure control independently of the main fuel delivery path, avoiding performance degradation.
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 effectively regulates delivery pressure by adjusting the angular relationship between the inlet and outlet, enhancing the operational performance of the fuel pump under varying conditions and maintaining fuel delivery pressure at setpoints, thereby improving the overall efficiency of the aircraft engine fuel system.
Implementation Method 1
an impeller disposed at least in part in the impeller cavity
Implementation Method 2
the pivoting the first part relative to the second part includes actuating, by the fluid downstream of the impeller, a passive pressure regulating mechanism
Data Source
AI summary
A method of controlling a delivery pressure of an aircraft engine fuel system includes operating a rotodynamic fuel pump hydraulically connected to the fuel system to pump a fluid from an inlet of the rotodynamic pump and out of an outlet of the rotodynamic pump for delivery to the fuel system. The method further includes varying an angular relationship between the inlet and the outlet of the pump to control the delivery pressure. An aircraft engine fuel system and a rotodynamic pump are also described.