Centrifugal Fan Impeller Protrusions Vortex Division
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing impeller vanes in centrifugal fans have poor pneumatic performance and high noise due to severe flow separation and vortex formation on their smooth curved surfaces.
Innovation Solution
The impeller design features cylindrical support members with bent vanes that include protrusions on the suction surface, arranged in staggered rows along the width direction, which regulate fluid flow by dividing large vortices into smaller ones, reducing friction resistance and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If smooth curved vane surfaces are used, then the structure is simple and easy to manufacture, but flow separation is serious and vortices are formed causing poor pneumatic performance and high noise
Solution Approach 1:
The patent applies local quality by adding protrusions only at specific locations (front edge area) of the vanes rather than modifying the entire vane surface. This localized modification improves flow control and reduces vortices while maintaining the overall simplicity of the vane structure and ease of manufacture.
Solution Approach 2:
The patent segments the vane surface by adding discrete protrusions that divide the flow into smaller channels. This segmentation of the flow path prevents large vortex formation and reduces flow separation, improving pneumatic performance while keeping the base vane structure simple.
2Ease of manufacture
If smooth curved vane surfaces are used, then the manufacturing process is simple, but noise is high due to vortex formation
Solution Approach 1:
The protrusions are added only at the front edge area of the vanes, applying local quality modification to control vortex formation at the critical location where flow separation initiates. This reduces noise generation while maintaining simple manufacturing processes for the overall vane structure.
Solution Approach 2:
The protrusions segment the flow into smaller streams, preventing the formation of large coherent vortices that generate noise. This flow segmentation reduces turbulent fluctuations and noise while requiring minimal modification to the vane manufacturing process.
3Reliability
If protrusions are added to regulate flow, then pneumatic performance improves and noise reduces, but device complexity increases
Solution Approach 1:
The patent uses local quality by adding protrusions only at the front edge area of the vanes rather than modifying the entire vane surface. This localized approach improves pneumatic performance through better flow control while minimizing the increase in overall device complexity.
Solution Approach 2:
Instead of trying to eliminate vortices through complex curved surface designs, the patent inverts the approach by adding small protrusions that work with the flow to break up vortices into smaller elements. This simpler inverted approach achieves better pneumatic performance without significantly increasing device complexity.
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 improves the pneumatic performance and reduces noise by minimizing friction resistance through the regulation of fluid flow and dissipation of kinetic energy, resulting in enhanced centrifugal fan performance.
Implementation Method 1
During the flow regulation process, a large vortex in the fluid can be divided into several small vortices, the top direction of the vortices is consistent with the fluid moving direction, and the bottom direction of the vortices is opposite to the fluid moving direction
Implementation Method 2
Such small vortices have smaller friction resistance, and the kinetic energy dissipated from the motion of the small vortices themselves can be partially cancelled out
Implementation Method 3
Impeller for centrifugal fan and centrifugal fan
Data Source
AI summary
The present application discloses an impeller for a centrifugal fan and a centrifugal fan. The impeller comprises a support member and several vanes. The support member has an inner wall that defines a hollow portion. The several vanes are arranged inside the hollow portion, each of the several vanes is connected with the inner wall and extends along the axial direction of the support member, and the several vanes are arranged along the circumferential direction of the support member. Each of the several vanes is bent and comprises a front edge, a tail edge, a convex suction surface, and a concave pressure surface, the suction surface and the pressure surface are arranged to oppose each other, and the front edge and the tail edge are arranged to oppose each other, wherein the tail edge is connected with the inner wall of the support member, and wherein several protrusions are provided on the suction surface, and the several protrusions are arranged to be close to the front edge. The protrusions can regulate the flow of a fluid immediately when the fluid contacts the vanes. During the flow regulation process, a large vortex in the fluid can be divided into several small vortices. Such small vortices have smaller friction resistance, and the kinetic energy dissipated from the motion of the small vortices themselves can be partially cancelled out, thereby reducing the noise of the impeller and improving the performance of the centrifugal fan.