Partial Cavity Baffles for Gas Turbine Airfoil Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In gas turbine engines, existing baffle configurations that extend fully through airfoil cavities result in high Mach numbers and heat transfer coefficients, leading to inefficient cooling and increased pressure loss, while also adding weight due to thick walls in some areas.
Innovation Solution
Partial baffles are configured within airfoil cavities, extending only partially from the inner to the outer diameter, with tapered or wedged designs to control airflow and reduce weight, allowing for improved cooling effectiveness and uniform temperature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If full-length baffles are used to occupy space within the internal cavity, then cooling coverage is improved, but Mach numbers become too high and pressure loss increases
Solution Approach 1:
The baffle is divided into multiple segments along its length, with each segment positioned at specific locations within the cavity rather than forming a continuous structure. This segmentation allows cooling flow to pass through gaps between segments, reducing Mach numbers and pressure loss while maintaining cooling effectiveness at critical areas.
Solution Approach 2:
Different portions of the cavity receive different levels of cooling based on local thermal requirements. The baffled regions provide enhanced cooling where heat transfer is needed, while unbaffled regions allow lower Mach number flow to reduce pressure loss. This local differentiation optimizes the balance between cooling effectiveness and pressure loss.
2Temperature
If full-length baffles are used to occupy space within the internal cavity, then cooling coverage is improved, but weight increases due to thick walls
Solution Approach 1:
The baffle structure is segmented to occupy only portions of the cavity space rather than extending fully through the airfoil. This reduces the amount of material required while maintaining cooling effectiveness in critical regions, thereby reducing overall airfoil weight.
Solution Approach 2:
Instead of providing full-length baffling throughout the entire cavity, the invention uses partial baffles that extend only through specific portions of the cavity. This partial action is sufficient to achieve the desired cooling effectiveness while minimizing material usage and weight.
3Speed
If cooling flow cross-sectional area is increased at the inner diameter, then low Mach numbers are maintained, but heat transfer efficiency decreases where cooling is needed
Solution Approach 1:
The cavity is divided into regions with different cross-sectional areas for cooling flow. At the inner diameter, larger cross-sectional area maintains low Mach numbers, while at the outer diameter where cooling is needed, smaller cross-sectional area creates high Mach numbers for enhanced heat transfer. This local differentiation resolves the contradiction between Mach number control and heat transfer efficiency.
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 partial baffle configuration enhances cooling efficiency while minimizing weight and pressure loss, achieving a more uniform temperature profile and reduced material usage compared to full-baffle designs.
Implementation Method 1
the cross-sectional area of the internal cooling flow may be configured to vary so that Mach numbers remain low where heat transfer is not needed (typically the inner diameter) and high Mach numbers where heat transfer is needed (typically the outer diameter)
Implementation Method 2
cooling air may be configured to flow through an internal cavity of an airfoil to prevent overheating
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
An airfoil (302) of a gas turbine engine having a hollow body defining at least one airfoil cavity (304) therein, the hollow body defining an inner diameter and an outer diameter and a baffle (320) positioned within the at least one airfoil cavity (304) and extending over less than an entire length between the inner diameter and the outer diameter, the baffle (320) configured to reduce the cross-sectional area within the at least one airfoil cavity (304). The at least one airfoil cavity (304) includes a first portion (326) having a length that is defined by an open cavity having a full cross-sectional area and a second portion (328) having a length that is defined by a reduced cross-sectional area, the second portion (328) being the length of the baffle (320) within the at least one airfoil cavity (304).