Impeller Blade Slots for Uniform Airflow and Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional heat dissipation fans experience uneven airflow distribution across blades, leading to pressure differences, turbulence, noise, and reduced heat dissipation performance due to unregulated airflow and vortex formation.
Innovation Solution
The impeller design features blades with alternating first and second slots of specific width and depth ratios (1.6 to 2.8) and radial angles, which reduce pressure differences and noise by optimizing airflow distribution, and an arc-shaped cross-section to minimize friction and enhance airflow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional fan blades rotate around a central axis, then the fan can move air, but uneven velocity distribution of airflow occurs across the fan
Solution Approach 1:
The blade is segmented into multiple sections along its span, with each section having different slot configurations. First slots and second slots are arranged at different positions and orientations to address airflow variations at different radial locations, transforming the blade from a uniform structure to a segmented one that can handle non-uniform airflow distribution
Solution Approach 2:
Different regions of the blade are given different local characteristics through varying slot depths, widths, and orientations. The first slots have different dimensions than the second slots, and their depths and orientations are optimized for specific radial positions, ensuring that each local region of the blade addresses the specific airflow conditions at that location
2Force
If pressure difference is generated at different positions on the blade, then airflow can be driven, but turbulence and vortex formation occur
Solution Approach 1:
The pressure difference generation is segmented across different blade sections rather than being uniform. First slots and second slots create localized pressure adjustments at different radial positions, breaking up the large-scale pressure gradient that causes turbulence into smaller, controlled pressure variations throughout the blade span
Solution Approach 2:
The slot dimensions (depth, width, orientation) are varied as parameters to control pressure distribution. By changing these geometric parameters across different blade sections, the pressure difference is optimized to drive airflow while preventing the excessive pressure gradients that lead to turbulence and vortex formation
3Productivity
If slots are added to the blade to regulate airflow, then heat dissipation performance improves, but blade structure becomes more complex
Solution Approach 1:
The blade structure is segmented with slots integrated into different sections, allowing airflow regulation without requiring a completely redesigned complex structure. The segmented slot configuration achieves heat dissipation improvement while maintaining relative structural simplicity through modular integration
Solution Approach 2:
The blade incorporates slot structures that create controlled porosity or open passages within the blade structure. These slots allow air to pass through the blade, improving heat dissipation performance while the slot geometry is designed to maintain structural integrity and avoid excessive 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
This design improves heat dissipation performance while reducing noise by ensuring uniform airflow and minimizing vortex formation, with optimal performance achieved at a ratio of 1.6 to 2.8 and radial angles of 120°, balancing airflow and noise reduction.
Implementation Method 1
A pressure difference may be generated at these different positions on the blade due to the difference in the amount of airflow
Implementation Method 2
Such pressure difference may cause turbulence along a direction perpendicular to the central axis
Data Source
AI summary
A three-bladed impeller providing a cooling airflow in air, with increased heat-dissipating efficiency and reduced noise includes a hub and three blades, the blades are arranged around the hub. Each blade is arched along its axial length from the front of fan to the back and also arched radially from the hub end of each blade to the outside tip. The back edge of each blade includes first and second slots, arranged alternately, the width of each first slot is λ1, the width of each of each second slot is λ2, the comparative sizes between λ2 and λ1 are in a ratio range of 1.6:1 to 1.8:1 (λ2:λ1).