UNSW Rocketry team

The project was aimed at designing and manufacturing a solid rocket propelled rocket which would reach the apogee of 10000 feet to compete in the Australian University Rocketry Competition(AURC).

Role Description

I served as a Structural simulation and Manufacturing engineer for the UNSW Rocketry team . My main responsibilities included:

Preparing CAD models for the Rocket structures using SOLIDWORKS.
Validation of the Mechanical/structural components to qualify for the launch Using ANSYS.
Running Dynamic structural and CFD simulation to study rocket failure phenomenon and ensuring the natural frequencies are well within control.
Procurement of Materials needed to mount the sub-systems of the Rocket.
Composite modelling and manufacturing of the rocket structures most of the rocket components were made out of composites.

UNSW Rocketry team during visit to NSW rocketry Association launch site (NSWRA) in Mullaly, NSW

As a preparation to understand the rocket dynamics , I joined UNSW rocketry team in to NSWRA launch site in Mullaly, NSW. There we tested our self built medium powered rockets. The experience was a stepping stone to build more powerful rockets.

Figure: Myself assembling medium powered rocket

Figure: Assembly of the rocket before launch

Detailed Designs

Bulkhead

The bulkhead is the component which maintains the contact between the recovery system and the rocket structure. It implies that this component has to withstand the high g forces and the load of the structure. In order to test its failure mode the bulkhead was simulated, to

Figure: SOLIDWORKS simulation of the bulkhead

Figure: ANSYS Simulation of the Bulkhead with symmetry

Fins

Fluttering is the phenomenon observed when the fins are subjected to inertial and aerodynamic load combined. The Fluttering is the phenomenon based on the stiffness and not the strength of the material selected. To model the fluttering phenomenon in ANSYS, initially a CFD simulation of the fins is to be carried out to analyse the pressure map of the fin surface. This result from CFD is used as a load in the structural analysis. The Fluent CFX analysis is used in modelling the fluttering. The shear transport model is used to simulate the effects of the thermal environment and the turbulence. Also, the additional expression to calculate the force on the fins is used. The FEA analysis can be carried out using the structural analysis combined with the modal analysis. This enables us to combine the effects of the equivalent stress to find the deformation of the fins at different frequencies. This gives the frequency at which there is maximum chance of failure. The loading cases for the structural analysis can be imported from CFD results and a fixed support is given to the left edge of the model. Structured meshing of the fins is to be made so that the model has the highest quality of meshing. The left edge of the fin is given the fixed region and inertial load such as mass of fin are also considered. The results of deformation at different frequency are shown in the diagram.

Figure: Multiphysics Model setup to study Aero-elasticity

Figure: Pressure mapping of the fins

Figure: Aeroelasticity study of the Fins when in contact with high velocity air

Rocket Motor Mount Structure

The rocket motor structure was found to be one of the most critical component which could cause failure of the mission. The study of the rocker motor mount structure had been carried out first using solid work to get a brief idea of stress concentration zones and then developed in to the high fidelity model in ANSYS. The results shown represents the stress distribution on the motor mount when the solid rocket motors are in firing state.

Figure: Motor mount simulation in (SOLIDWORKS)- Equivalent Stress

Figure: Motor mount MESH

Figure: Motor mount ANSYS Simulation ( Equivalent Stress)