Optimization Method of Impeller Blades of Low Pressure Axial Flow Fan

Abstract

The invention discloses an optimization method for impeller blades of a low-pressure axial flow fan. Low-pressure axial flow fans are widely used, but there are problems of low total pressure, large air volume, and low impeller efficiency. In the present invention, a blade of the impeller model to be optimized is divided into n sections along the radial direction of the impeller, and the chord length bi, the outlet geometric angle β2A(i) and the inlet airflow angle β1(i) of the n sections are obtained. Draw a sketch, the sketch includes the first line segment, the second line segment, the third line segment, the fourth line segment, the fifth line segment, the sixth line segment, the first arc, the second arc, the seventh line segment and the eighth line segment. The first arc and the second arc form a new type of line. According to the new line, n new sections are obtained, and the optimized impeller model is obtained according to the n new sections. The present invention can optimize the performance of the low-pressure axial flow fan only by knowing the chord length of the blade section to be optimized, the inlet flow angle and the outlet geometric angle, greatly reducing the design time and cost.

Description

technical field [0001] The invention belongs to the technical field of fan impellers, and in particular relates to an optimization method for blades of a low-pressure axial flow fan impeller. Background technique [0002] Low-pressure axial flow fans are widely used as the main power of industrial equipment and household appliances such as ventilation, HVAC, cooling, air conditioning and transportation. The aerodynamic characteristics of the axial flow fan are low total pressure, large air volume, and low impeller efficiency. The reason is that there is a gap between the blade and the pipe, there is a secondary flow at the top of the blade, the blade root is connected to the hub, and the separation flow is also serious. There are a large number of vortices near the tip of the blade, and even backflow, causing a large flow loss. [0003] In an axial flow fan, the pressure loss when the airflow passes through the blades is very complicated, and the pressure loss distribution ...

AI Technical Summary

Problems solved by technology

Therefore, there is a transverse pressure gradient in the boundary layer, but there is no or very little centrifugal force of the airflow, so the transverse gradient pressure in the boundary layer cannot be balanced, and the gas in the boundary layer will flow from the concave surface of one blade to the other. The lateral flow of the convex surface adjacent to the blade reduces the pressure in the boundary layer near the concave surface of the blade, while the pressure increases near the convex surface of the adjacent blade, thus forming a vortex

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