Projects on Numerical Computation

Four projects I finished in AEROSP 423 Computational Methods for Aerospace Engineering. Each one focuses on one type of numerical methods. More details can be found in the reports attached at the bottom of this page.

Project 1: Meteor Strike?

Simulate the trajectory of a meteor which has a close encounter with the Earth using Forward Euler, Predictor corrector and RK4. Four different initial trajectory angles are given, which can cause different results (escape, light aerobrake, hard aerobrake and quick crach), as shown in Figure 1. For the cases impact happens, calculate the location, time, speed at impact point via linear interpolation. Finally, for the quick crash case, assuming that we are able to change the velocity of the meteor, find the minimal velocity change which avoids the Earth impace using nonlinear programming.

Project 2: Flow Over A Building

Model the flow of air over a rectangular building, assuming the fluid is incompressible and irrotational. Use finite difference on a uniform grid to discretize the PDEs and construct a linear system of equations, which are solved to get the discretized steam function, as shown in Figure 2. With the steam function, compute the pressure coefficent of the building roof and the lift coefficient of the building.

Project 3: Nozzle Flow

Assume that a flow is governed by Euler equation of gas dynamics. Simulate the flow in a two-dimentional rocket nozzle, the shape shown in Figure 3, using second-order finite volume method on quadrilateral meshes. The field quantities (mach number and pressure) can be ploted based on the numerical result of flow, as shown in Figure. 3. Finally, calculate the coefficient of thrust and entropy error, an indicator of numerical error, based on the solution.

Project 4: A Metal-Matrix Composite Insulator

The metal-matrix composite (MMC), i.e. metal mixed with granules of a low-conductivity ceramic, have better insulating properties than the original metal. The projet aims to analyze the relationship between the size of granules and the insulating property of MMC.

Consider the intersection of a metal plate with square granules of ceramic distributed evenly, where the heat is conducted from one side to the other side, as shown in Figure 4. When we change the size of granules, the thermal conductivity changes too, which results in a different temperature distribution. For one specific granule size, the temperature distribution, shown in Figure 5, can be calculated by a finite element method. Then, the average thermal conductivity of that MMC can be obtained from the temperature distribution.

The project tests four different sizes of granules. The result shows that larger granules will lead in lower thermal conductivity, that means better insulating properties.

Figure 1. Simulation of Meteor Trajectories with Different I.C. (Blue Circle: the Earth; Red line: Meteor Trajectories)

Figure 2. Numerical Result of Steam Fuction

Figure 3. Mach Number and Pressure Fields

Figure 4. Intersection of MMC Plate (red square: granule of low-conductivity ceramic; blue region: metal)

Figure 5. Temperature Distribution of MMC in Fig. 4