Header Duct Transition Geometry for Low Pressure Loss

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Solution Overview

Problem

Existing header duct designs suffer from high pressure loss and reduced flow uniformity due to flow separation regions, which limit the performance of components like heat exchangers by increasing pressure loss and concentrating flow through some passages, thereby reducing efficiency.

Innovation Solution

A header duct with a transition portion featuring a non-monotonic cross-sectional area distribution, including a bulbous region and protrusion along the inside radius of the bend, which reduces flow separation and pressure loss by smoothly transitioning from a circular inlet to rectangular outlets, ensuring more uniform fluid distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple monotonic transition is used from circular inlet to rectangular outlets, then the device complexity is reduced and ease of manufacture is improved, but pressure loss increases and flow uniformity deteriorates due to flow separation regions

Engineering Contradiction:

Improveease of manufactureVSAvoidpressure loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The transition portion incorporates a non-monotonic cross-sectional area distribution with a bulbous region and protrusion specifically positioned along the inside radius of the bend. This local geometric modification creates favorable pressure gradients that eliminate flow separation regions, thereby reducing pressure loss without requiring complete redesign of the entire duct system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The bulbous region introduces a curved, non-linear transition in the cross-sectional area distribution along the inside radius of the bend. This curvature modification smooths the flow path and eliminates abrupt changes that cause flow separation, reducing pressure loss while maintaining manufacturability through standard duct forming processes.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Ease of manufacture

If a simple monotonic transition is used from circular inlet to rectangular outlets, then the device complexity is reduced and ease of manufacture is improved, but flow uniformity deteriorates due to flow separation regions concentrating flow through some passages

Engineering Contradiction:

Improveease of manufactureVSAvoidflow uniformity

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The non-monotonic cross-sectional area distribution with bulbous region and protrusion is strategically positioned along the inside radius of the bend to locally modify flow behavior. This creates favorable pressure gradients that prevent flow separation and promote uniform flow distribution to all outlets, improving flow uniformity without complicating the overall manufacturing process.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If the transition portion uses a non-monotonic cross-sectional area distribution with bulbous region and protrusion, then pressure loss is reduced and flow uniformity is improved, but the device complexity increases

Engineering Contradiction:

Improvepressure lossVSAvoiddevice complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The complex non-monotonic cross-sectional area distribution is localized specifically to the transition portion along the inside radius of the bend, rather than requiring complexity throughout the entire duct system. This allows pressure loss reduction through targeted geometric modification while keeping the inlet and outlet portions simple and easy to manufacture.

Inventive Principle:

Principle #3Local quality

4Loss of energy

Engineering Contradiction:

Improvepressure lossVSAvoidease of manufacture

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The non-monotonic cross-sectional area distribution with bulbous region and protrusion is confined to the transition portion, allowing the majority of the duct (inlet and outlet portions) to maintain simple geometries that are easy to manufacture. The localized complexity can be achieved through standard duct forming processes without requiring advanced manufacturing techniques.

Inventive Principle:

Principle #3Local quality

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

The design significantly reduces pressure loss and improves flow uniformity, allowing for increased efficiency and larger passage geometries in heat exchangers by eliminating flow separation regions and enhancing fluid flow distribution.

Implementation Method 1

flow separation regions, which create a region of turbulent flow and effectively reduce the cross-sectional area of duct 10 near the separation region

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Data Source

PatentUS11415378B2Inlet header duct design features

Publication Date: 2022.08.16 HAMILTON SUNDSTRAND CORP

AI summary

A header duct and method of forming a header duct includes an inlet portion having a planar inlet, an outlet portion have a plurality of planar outlets, and a transition portion extending continuously from the inlet portion to the outlet portion. The transition portion has a bend and internal topography defining a non-monotonic cross-sectional area distribution between the inlet and outlet portions. The transition portion can further include a bulbous region extending in a lateral direction of the duct and a protrusion located along an inside radius of the bend.