Delta Fuselage VTOL Aircraft with Rotatable Proprotors

Solution Overview

Problem

VTOL aircraft often face a trade-off between stability in vertical flight and performance in horizontal flight, as their design optimizes for one mode at the expense of the other.

Innovation Solution

A VTOL aircraft design featuring a delta-wing shaped fuselage with rotatable proprotors and swept-back winglets, allowing for enhanced lift and thrust generation in both vertical and horizontal flight modes, with a center of lift point optimized for improved aerodynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If VTOL aircraft are designed to optimize vertical flight stability, then vertical flight performance is improved, but horizontal flight performance deteriorates

Engineering Contradiction:

Improvevertical flight stabilityVSAvoidhorizontal flight performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The aircraft employs rotatable proprotors that can dynamically change orientation between vertical and horizontal flight modes. The proprotors rotate to align with the desired flight direction, allowing the same propulsion system to optimize performance for both vertical takeoff/landing and horizontal cruise operations, thereby resolving the trade-off between vertical stability and horizontal performance

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The aircraft changes operational parameters by rotating the proprotors to different angular positions. In vertical flight mode, the proprotors are oriented vertically for optimal lift generation and stability. In horizontal flight mode, the proprotors rotate to a horizontal orientation for optimal thrust generation, thus adapting the propulsion configuration to match flight requirements and eliminate the performance trade-off

Inventive Principle:

Principle #35Parameter changes

2Productivity

If VTOL aircraft are designed to optimize horizontal flight performance, then horizontal flight capability is improved, but vertical flight stability deteriorates

Engineering Contradiction:

Improvehorizontal flight performanceVSAvoidvertical flight stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The aircraft employs rotatable proprotors that can dynamically change orientation between vertical and horizontal flight modes. The proprotors rotate to align with the desired flight direction, allowing the same propulsion system to optimize performance for both vertical takeoff/landing and horizontal cruise operations, thereby resolving the trade-off between vertical stability and horizontal performance

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The aircraft changes operational parameters by rotating the proprotors to different angular positions. In vertical flight mode, the proprotors are oriented vertically for optimal lift generation and stability. In horizontal flight mode, the proprotors rotate to a horizontal orientation for optimal thrust generation, thus adapting the propulsion configuration to match flight requirements and eliminate the performance trade-off

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If swept-back winglets are added to the aircraft, then lift-to-drag ratio is improved, but device complexity increases

Engineering Contradiction:

Improvelift-to-drag ratioVSAvoidaircraft structure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The swept-back winglets are integrated with the existing wing structure, merging the high-lift device function with the primary wing. This combination approach improves the lift-to-drag ratio without adding separate, complex systems, as the winglets utilize the same structural framework and control mechanisms as the main wings

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The winglets feature swept-back geometry with curved surfaces that optimize aerodynamic flow. The swept-back angle and curvature are designed to reduce drag and improve lift characteristics, achieving better energy efficiency through aerodynamic shaping rather than through complex mechanical systems

Inventive Principle:

Principle #14Spheroidality (Curvature)

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

The design achieves high lift-to-drag characteristics, mitigates prop-whirl flutter, and allows for efficient transition between vertical and horizontal flight, enhancing mission distance and loiter capabilities.

Implementation Method 1

each of the proprotors being rotatable to generate lift in vertical flight

Methodology Applied

Scientific EffectAerodynamic lift: Aerofoil

Implementation Method 2

each of the proprotors being rotatable to generate thrust in horizontal flight

Methodology Applied

Scientific EffectAerodynamic thrust: Jet

Implementation Method 3

The fuselage has a center of lift point at about a 25-35% root chord location

Methodology Applied

Scientific EffectAerodynamic lift: Aerofoil

Implementation Method 4

a first winglet extending outwardly from a distal tip of the first wing portion, a second winglet extending outwardly from a distal tip of the second wing portion

Methodology Applied

Scientific EffectDrag reduction: Drag

Data Source

PatentUS10538322B2Delta fuselage for vertical take-off and landing (VTOL) aircraft

Publication Date: 2020.01.21 SIKORSKY AIRCRAFT CORP

AI summary

A vertical take-off and landing (VTOL) aircraft is provided. The aircraft includes a wing, nacelles supportively disposed at opposite ends of the wing, proprotors respectively attached to each of the nacelles with each of the proprotors being rotatable to generate lift in vertical flight and thrust in horizontal flight and a delta-wing shaped fuselage disposed along the wing between the nacelles.