A composite material-based automatic pitch propeller determination method

Abstract

The invention discloses a determination method for an automatic variable-pitch propeller based on a composite material. The determination method disclosed by the invention has the advantages that by design of the ply angle of the composite material, the beneficial torsional deformation occurs under the load action of centrifugal force, so that the automatic variable-pitch purpose of blades of the propeller is achieved; the propeller adopts the composite material (carbon fiber or glass fiber), and an elastic shaft with a specific angle is designed by utilizing the designability of the mechanical property of the composite material, so that the expected deformation effect of the structure with the composite material is realized under the load action, the variable-pitch function of the propeller in the small-angle range is realized and the operating range of the propeller is expanded.

Description

technical field [0001] The invention relates to a method for determining an automatic variable pitch propeller based on composite materials, and belongs to the technical field of unmanned aerial vehicle propulsion design. Background technique [0002] Near space solar-powered aircraft has great advantages in the fields of relay communication, military reconnaissance, etc. However, due to its low-speed operation in the near space with thin air, its propulsion system is generally selected as solar-electric-propeller propulsion. Near-space solar-powered aircraft generally fly at an altitude of 20km, where the air density is low, the temperature difference between day and night is large, and the environment is very harsh. In order to improve the reliability of the propulsion system and reduce the weight, fixed-pitch propellers are used, but it is difficult for fixed-pitch propellers to meet performance requirements when operating at high and low altitudes. . The traditional sol...

AI Technical Summary

Problems solved by technology

Near-space solar-powered aircraft generally fly at an altitude of 20km, where the air density is low, the temperature difference between day and night is large, and the environment is very harsh. In order to improve the reliability of the propulsion system and reduce the weight, fixed-pitch propellers are used, but it is difficult for fixed-pitch propellers to meet performance requirements when operating at high and low altitudes.

The traditional solution is to use high-power motors, but the weight of high-power motors increases a lot, and high-power operation is not required when cruising at high altitudes, so high-power motors occupy the limited carrying capacity of the aircraft and reduce the performance of the aircraft

[0003] In order to make the propeller have high efficiency in the whole working range, the traditional method is to use the method of variable pitch, but the torque variable mechanism is complex and heavy, which is not suitable for solar aircraft

However, if a fixed-pitch propeller is used, in non-design conditions, such as when flying at low altitude, because the air density on the ground is high, the propeller needs a large input power when it is working. At this time, the output power of the motor is difficult to meet the needs of the propeller. unable to work properly

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