Testing Plan

Testing key components of the team's design is crucial in order to ensure success at the competition. Testing was performed throughout the design and manufacturing process in order to refine and validate structural and electrical choices. The testing concludes with flight testing that helps improve the flying qualities and performance of the aircraft.

7.1 Flight simulation of final design

Testing was performed throughout the design and manufacturing process to verify design, methods, tools and assumptions used to size major aircraft components. All the components underwent testing in order to check their stability & above all to minimize their weight. Before actual fabrication analysis was done to check the validity of desired results. ANSYS 16.2 was used for flow analysis of aircraft. Structural analysis of wing was done using SOLIDWORKS while structural analysis of tail was done using ANSYS 16.2.

7.2 Surface analysis

For analyzing the aerodynamic characteristics of detail design of our aircraft, simulation on ANSYS 16.2 was performed using the finite element meshing (FEA) approach.

Several experiments were undertaken for different angle of attacks and inlet air velocity, but here only a single experiment results are discussed for the sake of understanding.

• Angle of attack = 0 degree.
• Inlet velocity = 26.7 m/s
• Outlet pressure = Atmospheric
• Steady state condition

Air properties at standard temperature & pressure S.T. P

CFD simulation on ANSYS FLUENT 16.2 was performed under the above-mentioned conditions and results were obtained to find the lift, drag. K - Epsilon turbulence model was used for analysis. Total number of nodes was 51,480, therefore the mesh is coarse. Hence our results were not exact.

Total drag force calculated = 22.31N (Pressure-drag=20.28N, viscous drag= 2.03 N) Total Lift force calculated = 160 N Cl = 0.37928, Cd = 2.3 x 10^-4

ANSYS simulation gave graphical 3D displays showing pressure distribution, velocity pattern, as well as stress distribution.

Figure shows static pressure distribution over entire aircraft body. From the results obtained it can be seen that maximum pressure distribution occurs at the leading edge & its value is 5.27x10² Pascal. The analysis shows that our design will be having stable lifting straight flight characteristics.

Figure shows static velocity distribution over entire aircraft body. From the results obtained it can be seen that at the leading edge, the velocity of incoming fluid is almost zero and it increases towards the trailing edge & at trailing edge its value is 40.9 m/s.

ANSYS simulation showed that our design was still very much aerodynamic. Fig shows velocity streamlines across the aircraft. There are no wake/disturbances in regions surrounding the aircraft fuselage and therefore fuselage body effects at the tail and elevator are negligible.

7.3 Structural Analysis

The optimum structural design of an aircraft is an important factor in the performance of the airplanes i.e. obtaining an aircraft with a high stiffness/weight ratio and sustaining the unexpected loading such as gust and maneuvering situations. Structural analysis was done by using finite element method. In this work the structural static analysis was achieved by using the ANSYS 16.2 in order to obtain stress, strain, strain energy and deformation in the wings & tail by using balsa wood.

7.3.1 Structural Analysis on Tail:

The whole analysis is based on pressure drag experienced by the tail and effects due to viscous drag are neglected since it is much smaller compared to pressure drag. Figure shows the stress distribution in the tail. From the Figure, it can be seen that maximum stress distribution in this part is 0.655 MPa.

Figure shows the total deformation in the tail for the given loading conditions. From the results obtained it can be seen that maximum deformation in this part is 3.3653x10^-5 m.

7.3.2 Structural Analysis on Wing

The actual structure of our aircraft wing is composed of balsa wood used with foam. But we analyze our wing by considering it to be composed of balsa only (ribs & spars included) because solid works couldn’t analyze composite structure.

Figure shows the maximum stress distribution in the wing for the given loading conditions. From the results obtained it can be seen that maximum stress distribution occurs at the center of the wing and its value is 1.207e+006 N/m²

7.4 Safety Checks Prior to Test Flight:

• All parts of the control systems and propulsion were tested according to mission requirements and rules:
• Propeller and motor selected for our plane were tested for thrust stand and flight. DDM was used to collect data for voltage and current that allows the
• Propulsion to verify and calibrate aircraft’s tools
• Receiver battery was tested on the ground under different flight loads
• With adequate channels, we selected a receiver to provide a sufficient voltage to the servos, as well as the required programming.
• Aircraft control surfaces were tested prior to the first flight.
• To verify the internal resistance of different batteries we tested Ni-Cd & NiMH Batteries to verify that they had sufficient cooling and they performed as expected.

7.5 Test Flight

The structure of final prototype was ready by 2nd week of February. During semester break (3^rd week of February) we worked on the inserting all the electronics in the aircraft. Aircraft was checked again for its center of gravity. With all the electronics installed airplane was ready for test flight on 20th February 2017.

7.6 Test flight day

First test flight was done on 20th February 2017. Aircraft was tested in the EME football ground as large clearing was required so as to avoid any sort of crash in the trees.

7.7 Aircraft Test Flights & Objectives

7.8 Conclusion

There was a room for a lot of improvement in the aircraft as it was underpowered, Currently as we submit this report, team is working on iterative combination of motors, speed controllers and batteries.