Nozzle Guide Vane Curved Conduit Bend for Cooling Flow Optimization

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Solution Overview

Problem

Existing nozzle guide vanes with integrally formed pre-swirl nozzles face challenges in optimizing cooling flow in the inter stage cavity of gas turbine engines due to limited flexibility in redirecting cooling flow to minimize turbulence, which results in inefficient cooling and increased energy loss.

Innovation Solution

A nozzle guide vane design featuring an angled nozzle with a curved conduit bend transition area, allowing for adjustable angles and diameters of the linear outlet part, which can be machined to optimize cooling flow direction and reduce turbulence, combined with a method of investment casting and machining to facilitate flexible redesign and minimize pressure losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an integrally formed pre-swirl nozzle is used, then the risk of free parts surfing in the inner plenum is avoided, but the flexibility to optimize cooling flow direction is limited

Engineering Contradiction:
Improverisk of free partsVSAvoidflexibility to optimize cooling flow
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The pre-swirl nozzle is divided into multiple independently manufacturable components: a core member with the curved conduit bend, and a nozzle body with the linear outlet part. These segments are joined together to form the complete nozzle assembly, allowing each segment to be optimized and manufactured separately while maintaining overall structural integrity and eliminating free parts risks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The core member with the curved conduit bend is manufactured in advance using investment casting with a ceramic core, creating a pre-formed transition area. This preliminary structure is then integrated with the nozzle body through machining operations, allowing the cooling flow path to be pre-optimized before final assembly.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If linear pipes with fixed angles are used, then manufacturing is simplified, but the ability to redirect cooling flow to minimize turbulence is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidturbulence and pressure losses
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The transition area of the pre-swirl nozzle incorporates a curved conduit bend instead of straight linear pipes. This curved geometry smoothly redirects the cooling flow from the radially outward direction to the angled outlet direction, minimizing flow separation and turbulence while maintaining manufacturing feasibility through investment casting techniques.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If the cooling flow angle is fixed during manufacturing, then production is easier, but redesign flexibility when boundary conditions change is reduced

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidredesign flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The nozzle is segmented into a core member and a nozzle body that can be manufactured and modified independently. The linear outlet part of the nozzle body can be remachined with different angles and dimensions without requiring complete redesign of the core member, enabling flexible adaptation to changing boundary conditions while maintaining efficient production of the core components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design allows dynamic adjustment of the cooling flow parameters through selective machining of the nozzle body. The linear outlet part can be reconfigured with different angles and diameters in response to changing operational requirements, making the system adaptable rather than static.

Inventive Principle:
Principle #15Dynamics

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 enhances cooling efficiency by reducing turbulence and energy loss in the inter stage cavity, providing flexibility for design changes and improved cooling air distribution with low pressure losses.

Implementation Method 1

optimize the cooling flow in the inter stage cavity between two stages of the gas turbine engine as the cooling flow has to be blown in a certain direction to minimize the turbulence in the inter stage cavity

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

providing flexibility for design changes and improved cooling air distribution with low pressure losses

Methodology Applied
Scientific EffectPressure losses: Pressure Drop

Data Source

PatentEP3124743B1Nozzle guide vane and method for forming a nozzle guide vane
Publication Date: 2021.04.28 ROLLS ROYCE DEUT LTD & CO KG
  • EP3124743B1 patent drawingFigure 1
  • EP3124743B1 patent drawingFigure 2
  • EP3124743B1 patent drawingFigure 3~4

AI summary

The present application relates to a vane (23) having an integral bent conduit (or pre-swirl nozzle) (39) in its inner platform (33) for conveying and orienting air coming from the internal cooling passage (35) of the vane to a cavity located under said vane. Said pre-swirl nozzle comprises a conical bend (41) that connects a radially outwards facing portion (42to a linear outlet part (36, 43). A method of forming such a vane is also disclosed. The method comprises investment casting metal (47) around a core member (38) that defines an internal cavity and internal features of the nozzle guide vane, and machining the obtained part to realize the outlet part (36, 43).