Design, Dynamics and Development of Upgraded Tiltable Wing associated Quadcopter through Advanced computational simulations incorporated Bottom-Up Approach

Abstract

This paper aims to design a hybrid quadcopter that can be used for multiple detecting applications in which its performance parameters are studied under various maneuverings such as forward and vertical movements based on computational studies. In order to enhance the endurance, the conventional rectangular cross-sectional arm was replaced by airfoil cross sectional arm which helps in reduction of overall drag. The proposed idea is a combination of both tilt wing and tilt rotor configurations to the hybrid unmanned aerial vehicle (HUAV). The CAD modeling of UAV components such as wing and propeller is done using Autodesk Fusion 360 and the fluid flow analysis is carried out using ANSYS Workbench 23 software. Different test cases including the Computational fluid dynamics (CFD), Fluid structure interaction (FSI) analysis are executed to estimate the performance of the configuration. Analyzing from a stability point of view, a mathematical model was designed for control of altitude increment, hold and forward velocity accordingly, and tuning of the controller was taken over. This UAV is capable of attaining stability during harsh environments which is analyzed using control dynamics study and controller design processes executed. As a preliminary work for validation, grid convergence study is performed to obtain reliable outcome for the computational study taken over, in addition to the execution of analytical validation for estimation of aerodynamic forces and deflection of wing due to impingement of drag force over frontal area of wing and experimental validations to determine the thrust produced by propeller. The steady fluid flow analysis is carried over for wing planform and transient flow analysis is done for both vertical and forward propellers using advanced CFD techniques. Based on the FSI approach, structural analysis was carried over for wing and propeller through which the material selection was done. From which, GY-70-CFRP composite was concluded as the best performing material by analyzing the performance parameters including total deformation etc., among various different imposed materials based on aerodynamical loading. Interpreting from the performed analyses, the proposed configuration seems to operate at less power considering the lift forces induced, which also enables it to reach better altitudes at less RPM. The structural efficiency happens to be achieved due to the reduction in the RPM as there is a contribution in lift production as the angle of attack of the proposed wing increases, which also decreases rotors' burden during forward motion and other maneuverings.

Keywords: Endurance enhancement; Energy conservation; Hybrid lift generation; Surveillance; Sustainability; Tilt wing.

Fig. 1

Workflow—Design approach.

Fig. 2

Weight estimation of HUAV using historical data.

Fig. 3

Wing loading estimation – tradeoff analysis.

Fig. 4

AR estimation – tradeoff analysis.

Fig. 5

Typical views and dimensions of modeled wing.

Fig. 6

Historical data of P/D ratio – tradeoff analysis.

Fig. 7

Typical Vertical Propeller Design.

Fig. 8

Vertical propeller – Top view.

Fig. 9

Typical forward propeller design.

Fig. 10

Forward propeller – Top view.

Fig. 11

Stick diagram of proposed HUAV – VTOL Operation – Top view.

Fig. 12

Stick diagram of proposed HUAV – VTOL Operation – Front view.

Fig. 13

Stick diagram of proposed HUAV – Cruise Operation – Top view.

Fig. 14

Stick diagram of proposed HUAV – Cruise Operation – Front view.

Fig. 15

Free body diagram – VTOL.

Fig. 16

Free body diagram – Forward flight.

Fig. 17

Thrust vs RPM – VTOL counter-clockwise propeller (1000 to 15,000 RPM).

Fig. 18

Lift curve slope of designed wing for Siachen conditions.

Fig. 19

3-axis alignment for designed shaft-propeller combination.

Fig. 20

Block diagram of proposed control method for the translational motion.

Fig. 21

Block diagram of the BLDC motor.

Fig. 22

Simulink model of the proposed altitude control system for the quadcopter.

Fig. 23

Altitude response of the UAV with tuned PID controller for VTOL and hold operations.

Fig. 24

Step response of the UAV with tuned PID controller at forward velocity.

Fig. 25

Flowchart of VTOL to Forward transition process.

Fig. 26

Altitude response of VTOL to Forward transition of the HUAV.

Fig. 27

Generated enclosure of wing with imposed conditions.

Fig. 28

Generated enclosure of propeller MRF with applied specifications.

Fig. 29

Discretized structure of Wing.

Fig. 30

Discretized structure of Propeller with SMRF.

Fig. 31

Named mesh formation in the transient case of propeller’s CFD analysis.

Fig. 32

Discretized wing model inside control volume.

Fig. 33

Mesh in propeller tip within control volume.

Fig. 34

Mesh in the wing model alone.

Fig. 35

Mesh on the propeller hub alone.

Fig. 36

Grid convergence study – Induced Velocity plot for wing.

Fig. 37

Grid convergence test – Pressure plot for vertical propeller.

Fig. 38

Depiction of cantilever beam supported on both sides with its equivalent.

Fig. 39.

3D printed VTOL propeller.

Fig. 40

Propeller assembly mounted on static thrust test setup.

Fig. 41

Propeller along with motor and ESC assembly.

Fig. 42

Propeller Operating at 4900 RPM – Displays 91.87 g Thrust.

Fig. 43

Pressure over the forward propeller – front view – 3900 RPM.

Fig. 44

Streamline along the forward propeller – 3900 RPM.

Fig. 45

Streamline along VTOL propeller – 4900 RPM.

Fig. 46

Pressure along the forward propeller – 4900 RPM.

Fig. 47

Thrust comparison of experimental and CFD results for different RPMs.

Fig. 48

Induced Velocity over wing – VTOL Operation.

Fig. 49

Pressure distribution on the wing surface – VTOL Operation.

Fig. 50

Induced Velocity over wing – Cruise Operation.

Fig. 51

Pressure distribution over the wing surface – Cruise Operation.

Fig. 52

Streamline along the rotating VTOL clockwise propeller—1000 RPM.

Fig. 53

Induced Velocity profile along the rotating VTOL clockwise propeller—10,000 RPM.

Fig. 54

Thrust variation with respect to varying RPM – VTOL clockwise propeller.

Fig. 55

Streamline along the rotating VTOL counter-clockwise propeller—10,000 RPM.

Fig. 56

Induced Velocity along the rotating VTOL counter-clockwise propeller—5000 RPM.

Fig. 57

Thrust variation with respect to varying RPM – VTOL counter-clockwise propeller.

Fig. 58

Streamline along the rotating forward clockwise propeller—1000 RPM.

Fig. 59

Velocity vector along rotating forward clockwise propeller—10,000 RPM.

Fig. 60

Thrust variation with respect to varying RPM – Forward clockwise propeller.

Fig. 61

Streamline along the rotating forward counter-clockwise propeller −10,000 RPM.

Fig. 62

Pressure distribution along the rotating forward counter-clockwise propeller—1000 RPM.

Fig. 63

Thrust variation for varying RPM – Forward counter-clockwise propeller.

Fig. 64

Discretized structure of propeller.

Fig. 65

Discretized structure of wing.

Fig. 66

Total deformation of wing during forward flight – GY-70-CFRP.

Fig. 67

Equivalent elastic strain on the wing during VTOL operation—Titanium Alloy.

Fig. 68

Equivalent stress on the wing during forward flight – Polyethylene.

Fig. 69

Total deformation variations for CFRP based composites over wing.

Fig. 70

Total deformation variations for other relevant composites over wing.

Fig. 71

Equivalent stress variations for CFRP based composites over wing.

Fig. 72

Equivalent stress variations for other relevant composites over wing.

Fig. 73

Stress vs strain profile variations for CFRP based composites over wing.

Fig. 74

Stress vs strain profile variations for other relevant composites over wing.

Fig. 75

Comparison of stress vs strain and density for CFRP composites over wing.

Fig. 76

Comparison of stress vs strain and density for other composites over wing.

Fig. 77

Total deformation on the forward propeller – GY-70-CFRP.

Fig. 78

Equivalent elastic strain on the forward propeller – BFRP.

Fig. 79

Equivalent stress on the forward propeller – Polyethylene.

Fig. 80

Total deformation variations for CFRP based composites over propeller.

Fig. 81

Total deformation variations for other relevant composites over propeller.

Fig. 82

Equivalent stress variations for CFRP based composites over propeller.

Fig. 83

Equivalent stress variations for other relevant composites over propeller.

Fig. 84

Stress vs strain profile variations for CFRP based composites over propeller.

Fig. 85

Stress vs strain profile variations for other relevant composites over propeller.

Fig. 86

Comparison of Stress vs strain and density for CFRP composites on propeller.

Fig. 87

Comparison of Stress vs strain and density for other composites on propeller.