Tail-Sitter Wing Layout With Staggered Engines for Aerodynamic Efficiency

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Solution Overview

Problem

Tail sitters face geometrical and operational constraints due to their vertical Take-off and landing position, which limits their aerodynamic efficiency and performance, leading to abandonment in favor of more complex VTOL aircraft.

Innovation Solution

A tail sitter design with a closed front section wing and staggered engine placement, eliminating the need for complex support structures and tail fins, enhancing aerodynamic efficiency and simplifying the configuration while maintaining high cruising speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the tail sitter uses traditional half-wing configuration with engines mounted on complex support structures, then the engine placement is achieved, but the device complexity and weight increase significantly

Engineering Contradiction:
Improveease of manufactureVSAvoiddevice complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the wing structure and engine mounting into a single integrated closed front section configuration. The engines are positioned within the enclosed space formed by the wing's leading edge, eliminating the need for separate support structures, struts, and external mounting brackets that would add complexity and weight.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a traditional open half-wing configuration to a closed front section three-dimensional enclosure. This dimensional change creates an integrated structure where the wing itself forms the engine mounting framework, reducing the number of separate components and simplifying the overall device architecture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the tail sitter uses closed front section wing with staggered engine placement, then aerodynamic efficiency is improved, but the structural design becomes more challenging

Engineering Contradiction:
Improveaerodynamic efficiencyVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies different functional qualities to different regions of the wing structure. The closed front section creates a streamlined aerodynamic shape at the leading edge, while the staggered engine placement optimizes thrust vectoring and airflow management in specific zones, enhancing overall aerodynamic efficiency without requiring complex manufacturing throughout the entire structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The staggered arrangement of engines within the closed front section creates an asymmetric configuration that optimizes aerodynamic performance. This asymmetric placement allows for better airflow management and reduced interference effects, while the modular nature of the asymmetric design actually simplifies manufacturing by allowing independent optimization of each engine position.

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If the tail sitter eliminates tail fin and complex support structures, then device complexity is reduced, but structural stability may be compromised

Engineering Contradiction:
Improvedevice complexityVSAvoidstructural stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent combines the functions of the tail fin and engine support structures into the closed front section wing configuration. The enclosed leading edge structure provides both the aerodynamic stability previously requiring a tail fin and the engine mounting function, eliminating separate stability-enhancing components while maintaining structural integrity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The closed front section creates a streamlined, curved aerodynamic shape at the wing leading edge. This curved configuration naturally provides structural strength and aerodynamic stability without requiring additional bracing elements or tail fins, as the streamlined shape itself resists aerodynamic forces and maintains structural integrity.

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 aerodynamic efficiency and simplified construction, overcoming previous limitations and making tail sitters viable for medium/long haul routes with reduced complexity and weight.

Implementation Method 1

the thrust of the motors counters the weight of the tail sitter in Take-off/landing conditions and the aerodynamic resistance of the air in flight conditions

Methodology Applied
Scientific EffectThrust: Jet

Implementation Method 2

the thrust of the motors counters the weight of the tail sitter in Take-off/landing conditions and the aerodynamic resistance of the air in flight conditions

Methodology Applied
Scientific EffectAerodynamic resistance: Drag

Data Source

PatentEP3587259B1Tail sitter and related control method
Publication Date: 2022.08.10 LEONARDO SPA
  • EP3587259B1 patent drawingFigure 1~2
  • EP3587259B1 patent drawingFigure 3~4
  • EP3587259B1 patent drawingFigure 5~6

AI summary

A tail sitter aircraft (1, 1') is described that comprises: a fuselage (2) arranged vertically in a Take-off/landing position and transversely to a vertical direction in a cruising position of the aircraft (1, 1'); a single wing (4); two first engines (15a, 15b) configured to exert respective first thrusts directed along respective first axes (A) on the tail sitter (1, 1'); and at least two second engines (15c, 15d) rotating about respective second axes (A) arranged above the first axes (A) of the first engines (15a, 15b), with reference to the cruising position; the at least two second engines being configured to exert respective second thrusts directed along respective second axes (A) on the tail sitter (1, 1'); the first and second engines (15a, 15b; 15c, 15d) being carried by the single wing (4); the first axes (A) of the first engines (15a, 15b) and the second axes (A) of the second engines (15c, 15d) being arranged along said front section (C) of the single wing (4).