Axial Inducer Pump Grooves Reduce Backflow

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Pumps face issues with flow-induced instabilities, such as backflow, vortices, and cavitation at blade tips, which can lead to catastrophic failure, particularly due to the design limitations in pressurizing fluids effectively.

Innovation Solution

The axial inducer pump design incorporates a housing with internal grooves that are elongated in the circumferential direction and have specific pitch angles, both forward and aft, to guide fluid flow and reduce backflow by positioning blades and grooves in a way that the forward pitch angle of the grooves and aft pitch angle of the blades enhance fluid flow towards the outlet, minimizing instabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pump design without internal grooves is used, then the structure is simple, but flow-induced instabilities occur at blade tips causing backflow and potential catastrophic failure

Engineering Contradiction:

Improvepump reliabilityVSAvoidhousing structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The housing internal surface is segmented into multiple circumferential grooves that divide the fluid passage into separate channels. These grooves segment the flow path adjacent to blade tips, preventing uncontrolled backflow and vortex formation while maintaining structural integrity of the housing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circumferential grooves act as intermediary structures between the blade tips and the housing internal surface. They mediate the fluid flow by providing controlled pathways that guide fluid downstream, reducing direct interaction between backflowing fluid and blade tips, thereby preventing cavitation and instability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If blades are designed to pressurize fluid effectively, then pumping performance is improved, but flow-induced instabilities such as backflow and vortices increase at blade tips

Engineering Contradiction:

Improvefluid pressurization efficiencyVSAvoidflow-induced instabilities

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The grooves are specifically positioned adjacent to blade tips where flow instabilities occur, rather than uniformly throughout the entire housing. This local modification addresses the specific problem area of blade tip backflow while maintaining efficient fluid pressurization in the main flow path.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of modifying the blade geometry to reduce instabilities, the invention inverts the approach by modifying the housing internal surface with grooves. The grooves are elongated in the circumferential direction, opposite to the axial direction of fluid flow, creating a configuration that naturally guides fluid downstream and prevents backflow.

Inventive Principle:

Principle #13The other way round (Inversion)

3Stability of the object's composition

If grooves are added to the housing internal surface, then backflow is reduced and flow stability is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvefluid flow stabilityVSAvoidhousing manufacturing ease

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The grooves are designed with specific parameters including circumferential elongation, uniform axial spacing, and controlled depth and width dimensions. These parameter specifications provide a clear manufacturing target, allowing the grooves to be formed using standard machining or additive manufacturing processes while ensuring consistent flow stability performance.

Inventive Principle:

Principle #35Parameter changes

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 effectively reduces flow-induced instabilities by directing fluid flow downstream, reducing backflow and enhancing the overall efficiency and reliability of the pump operation.

Implementation Method 1

The internal surface of the housing defines a plurality of grooves adjacent the at least one blade tip. The grooves are elongated in a circumferential direction... effectively reduces flow-induced instabilities by directing fluid flow downstream

Methodology Applied

Scientific EffectFluid flow guidance:

Implementation Method 2

The rotor and blades rotate to pressurize fluid that enters the pump

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

a pump may include an inducer that may have one or more blades that extend from a rotor to a radially offset tip. The rotor and blades rotate to pressurize fluid

Methodology Applied

Scientific EffectImpeller pressurization: Impeller

Data Source

PatentUS11236764B2Pump with housing having internal grooves

Publication Date: 2022.02.01 AEROJET ROCKETDYNE INC

AI summary

A pump includes an axial inducer. The axial inducer includes a housing that has an internal surface that defines an axial fluid passage. A rotor is disposed about a central axis in the fluid passage. The rotor includes at least one blade that defines at least one blade tip. The internal surface of the housing defines a plurality of grooves adjacent the at least one blade tip. The grooves are elongated in a circumferential direction.