Booster Rotor Blade Spanwise Distribution for Weight and Stability
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Solution Overview
Problem
Gas turbine engines face inefficiencies and instability due to endwall meridional velocity deficits and foreign object encounters, which are not adequately addressed by existing technologies, leading to increased aerodynamic loading and weight issues in booster rotors.
Innovation Solution
The implementation of rotor blades with specific characteristic distributions, such as normalized chord, delta inlet blade angle, and normalized local maximum thickness distributions, which optimize efficiency and stability while maintaining robustness without increasing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the airfoil thickness is increased to provide robustness against foreign objects, then the robustness is improved, but the weight of the airfoil increases
Solution Approach 1:
The patent applies local quality by implementing a non-uniform thickness distribution along the span of the airfoil. Specifically, the normalized local maximum thickness has a minimum value between 60%-90% span, while maintaining adequate thickness at the root and tip regions where it is most needed for foreign object protection. This localized optimization provides robustness where required without unnecessarily increasing weight across the entire airfoil.
Solution Approach 2:
The patent employs parameter changes by optimizing the normalized local maximum thickness distribution as a specific geometric parameter. The thickness distribution is defined by having a minimum normalized local maximum thickness value at 60%-90% span, which changes the overall thickness profile to achieve better weight-to-robustness ratio while maintaining protective capabilities at critical locations.
2Reliability
If the airfoil thickness is increased to withstand foreign object encounters, then the robustness is improved, but the efficiency deteriorates
Solution Approach 1:
The patent applies local quality by implementing a non-uniform thickness distribution along the span of the airfoil. Specifically, the normalized local maximum thickness has a minimum value between 60%-90% span, while maintaining adequate thickness at the root and tip regions where it is most needed for foreign object protection. This localized optimization provides robustness where required without unnecessarily increasing weight across the entire airfoil.
Solution Approach 2:
The patent employs parameter changes by optimizing the normalized local maximum thickness distribution as a specific geometric parameter. The thickness distribution is defined by having a minimum normalized local maximum thickness value at 60%-90% span, which changes the overall thickness profile to achieve better weight-to-robustness ratio while maintaining protective capabilities at critical locations.
3Ease of manufacture
If conventional rotor blade designs are used, then the manufacturing is simpler, but the endwall aerodynamic loading management is insufficient leading to instability
Solution Approach 1:
The patent applies local quality through specific chord and inlet blade angle distributions that are optimized for different spanwise locations. The normalized chord has a minimum value between 20%-90% span, and the delta inlet blade angle has a minimum value between 10%-50% span, creating locally optimized aerodynamic characteristics that manage endwall loading and improve stability without requiring complex manufacturing processes.
Data Source
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AI summary
A rotor for a turbofan booster section associated with a fan section of a gas turbine engine includes a rotor blade having an airfoil having a leading edge, a trailing edge and a mean camber line. The airfoil has a delta inlet blade angle defined as a difference between a local inlet blade angle defined a spanwise location, and a root inlet blade angle defined at the root. The delta inlet blade angle decreases in the spanwise direction from the root to a minimum value at greater than 10% span and from the minimum value, the delta inlet blade angle increases to the tip. The rotor includes a rotor disk coupled to the rotor blade configured to be coupled to the shaft or the fan to rotate with the shaft or the fan, respectively, at the same speed as the shaft and the fan.