Turbomachine Blade Channel Saddle Surface Contours
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Solution Overview
Problem
Turbomachines experience secondary flows due to the deflection of fluid layers near walls, leading to vortices and pressure losses, which are not effectively reduced by existing side wall contouring methods.
Innovation Solution
A blade channel design with a saddle surface formed between alternating elevations and depressions on the side walls, where the elevations are arranged in the circumferential direction and depressions in the axial direction, reducing the static pressure field and secondary flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional side wall contouring is used, then the structure is simple, but secondary flows are not effectively reduced leading to pressure losses
Solution Approach 1:
The patent applies local quality by creating specific elevation and depression contours at particular locations on the side walls rather than uniform contouring. The elevations are positioned at the leading edge region and depressions at the trailing edge region, making the side wall structure non-uniform and location-specific to address secondary flow patterns locally where they occur most strongly
Solution Approach 2:
The patent employs curvature by forming elevation and depression contours with specific radii of curvature. The elevations have a first radius of curvature and the depressions have a second radius of curvature, creating smooth curved transitions that modify the pressure field distribution and reduce flow separation compared to sharp or flat contours
2Productivity
If side wall contours are introduced to reduce secondary flows, then pressure losses decrease, but the manufacturing complexity increases
Solution Approach 1:
The patent applies dynamics by making the side wall contours adjustable rather than fixed. The elevations and depressions can be modified in terms of their radii of curvature, positions, and dimensions to optimize performance for different operating conditions, allowing the structure to adapt to varying flow regimes and efficiency requirements
Solution Approach 2:
The patent uses parameter changes by varying the radii of curvature, positions, and dimensions of the elevation and depression contours. By adjusting these geometric parameters, the pressure field distribution can be optimized to reduce secondary flows and improve efficiency while maintaining manufacturing feasibility through controlled variation of key dimensions
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 design reduces secondary flows and associated pressure losses, improving the inflow onto subsequent blade rows and enhancing turbomachine efficiency.
Implementation Method 1
A fluid flow guided through a flow channel is regularly deflected parallel to side walls by a lateral pressure gradient
Data Source
Figure 1
AI summary
Disclosed is a blade channel of a turbomachine, which in the circumferential direction of the turbomachine is bounded by a pressure side of a blade and by an opposite suction side of an adjacent blade, which in the radial direction of the turbomachine is bounded by two opposite side walls, and which extends in the axial direction of the turbomachine between the leading edges and trailing edges of the blades, wherein at least one of the side walls is provided with local contours, of which at least two contours are formed as elevations and at least two contours as depressions, wherein a saddle surface is formed between the contours which in one revolution alternately transitions into an elevation and into a depression, a blade grid with such blade channels, and a turbomachine with such a blade grid.