Diagonal Fan Impeller Structure for Backflow and Noise Reduction
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Solution Overview
Problem
Conventional fans used in communication systems face inefficiencies in heat dissipation and noise levels under severe system conditions, necessitating improvements in fan characteristics and noise reduction.
Innovation Solution
A diagonal fan design with an optimized chamber and improved impeller, featuring a gradually expanding hub diameter, staggered guiding walls, and backflow channels to reduce backflow and turbulence, along with protrusions and indentations on the impeller for balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the fan operates under severe system conditions to maintain effective heat dissipation, then the heat dissipation efficiency is improved, but backflow and turbulence occur in the fan chamber
Solution Approach 1:
The chamber is segmented into a working chamber and a backflow channel through the guiding wall structure. The guiding wall extends from the inlet toward the outlet, creating distinct flow paths that separate the main airflow from backflow, allowing each segment to handle specific flow characteristics without interference
Solution Approach 2:
The conical section shell acts as an intermediary structure between the impeller and the chamber walls. It gradually expands the airflow direction from inlet to outlet, mediating the transition and preventing sudden flow direction changes that cause turbulence and backflow
2Productivity
If the outer diameter of the impeller hub is expanded from inlet to outlet, then the airflow efficiency is improved, but the device complexity increases
Solution Approach 1:
The impeller hub features a conical section with gradual curvature expansion from inlet to outlet. This curved geometry smoothly redirects airflow without sharp angles or sudden transitions, improving airflow efficiency while maintaining manufacturing feasibility through standard conical forming processes
Solution Approach 2:
The hub diameter parameter changes gradually along the axial direction from inlet to outlet, creating a tapered configuration. This continuous parameter change optimizes airflow velocity and direction across different radial positions, enhancing overall airflow efficiency
3Object-generated harmful factors
If the guiding wall is staggered and overlapped with the conical section shell, then backflow is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The guiding wall is positioned asymmetrically relative to the conical section shell, with staggered and overlapped configuration. This asymmetric arrangement creates an offset flow path that naturally prevents backflow from entering the working chamber, utilizing geometric asymmetry to control flow direction
Solution Approach 2:
The guiding wall is positioned upstream and overlaps with the conical section shell before the airflow reaches critical zones. This preliminary positioning intercepts potential backflow early in the flow path, preventing it from developing into significant turbulence before the air reaches the impeller
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
Enhances fan efficiency by minimizing backflow and turbulence, reducing wind resistance and noise, and improving airflow balance.
Implementation Method 1
the fan is mainly used to perform the forced convection on the system to achieve the purpose of heat dissipation
Implementation Method 2
the flow velocity and the kinetic energy of the flow field are reduced gradually. Therefore, the wind resistance between the inner wall surface of the frame, and the outer wall and the upper end of the conical section shell is increased
Data Source
AI summary
A diagonal fan is disclosed and includes a frame and an impeller. The frame includes an inlet, an outlet, and an accommodation space. The inlet and the outlet are communicated through the accommodation space. The impeller is accommodated within the accommodation space and includes a hub, a cylindrical part, a conical section shell and a plurality of blades, wherein the cylindrical part is configured to accommodate a rotor. The cylindrical part includes a plurality of protrusion portions and a plurality of indentation portions disposed on an inner surface thereof, and the plurality of protrusion portions are abutted against an outer surface of a magnetic shell of the rotor.