Rotorcraft Updraft Take-Off via Negative Pitch Inversion
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Solution Overview
Problem
Conventional rotorcrafts face challenges in vertical take-off, requiring high energy and power due to downdraft generation, limiting their ability to operate at higher altitudes, temperatures, or with increased weight.
Innovation Solution
The rotorcraft adjusts rotor blades to a negative pitch angle for take-off, generating an updraft that supplements lift, reducing energy consumption and allowing operation with less onboard energy by utilizing a ground-based station for pre-rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If rotor blades are adjusted to a higher angle of attack to increase lift during take-off, then lift force is improved, but energy consumption increases due to downdraft generation
Solution Approach 1:
The patent applies inversion by adjusting rotor blades to a negative pitch angle (negative angle of attack) during the initial rotation phase, which generates an updraft instead of the conventional downdraft. This inverted approach creates an upward force that supplements lift during take-off, reducing the energy required compared to conventional positive angle of attack operation.
Solution Approach 2:
The patent employs preliminary action by generating an updraft before the rotorcraft fully takes off. The rotor blades are set to a negative pitch angle and rotated to create an updraft that persists for several seconds, providing upward force assistance before the rotorcraft becomes fully airborne and before conventional lift generation begins in full effect.
2Adaptability or versatility
If rotorcraft uses conventional take-off with downdraft generation, then take-off is achieved, but operation at higher altitudes, temperatures, or with increased weight is limited
Solution Approach 1:
The patent applies the anti-weight principle by generating an updraft (upward force) that counteracts the weight of the rotorcraft during take-off. This upward force from the negative angle of attack rotation supplements the conventional lift, effectively reducing the net weight that the engine must overcome, thereby enabling operation at higher altitudes, temperatures, or with increased payload.
3Power
If rotorcraft stores more onboard energy for take-off, then take-off performance is improved, but device complexity and energy storage requirements increase
Solution Approach 1:
The patent applies self-service by using the rotorcraft's own rotor system to generate an updraft that assists take-off. Instead of requiring additional energy storage systems or external assistance, the rotorcraft uses its existing rotor infrastructure in an unconventional manner (negative pitch angle rotation) to create the beneficial updraft force, thereby improving take-off performance without adding 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 approach enables rotorcrafts to take-off with reduced power consumption, increased payload capacity, and operation at higher altitudes and temperatures by leveraging the persistent updraft force.
Implementation Method 1
The rotation of the plurality of rotor blades at the negative pitch angle generates an updraft that, during a subsequent vertical take-off operation, applies an upward force to the rotorcraft to supplement lift generated by the plurality of rotor blades
Data Source
AI summary
A rotorcraft includes a frame and an engine coupled to the frame. The rotorcraft also includes a rotor hub coupled to the engine and a plurality of rotor blades coupled to the rotor hub. Each rotor blade is configured to be adjusted to a negative pitch angle such that each rotor blade is oriented at a negative angle of attack. The rotation of the plurality of rotor blades at the negative pitch angle generates an updraft that, during a vertical take-off operation, applies an upward force to the rotorcraft to supplement lift generated by the plurality of rotor blades.