1: Aircraft Engine Mathematical Model

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... í µí°¿ = 7.2 í µí±š, inlet diameter í µí°· = 1.9 í µí±š, and two outputs, one for hot air path and the other for cold air path ( Fig. 3.1). The distance between the axis of the engine and the ground í µí°» = 1.55 í µí±š. The engine was enclosed by a rectangular box representing the surrounding air, with dimensions 90m (X) * 25m (Y) * 60m (Z) ( Fig. 3.2). The coordinate system chosen was such that positive X points into the inlet, positive Y points upwards, normal to the ground plane, and positive Z points in the direction of the crosswind. Figure 3.2 shows the domain and XYZ coordinate system described, as well as the names assigned to each of the domain surfaces, with the ground ...

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... hypermesh was generated using The ICEM CFD 17.2 for the geometry illustrated in Figure 2.2. For capturing surface details, "A patch dependent" method was used to create the 2D triangles surface mesh, and "Quick (Delauny)" method was used to generate the 3D tetrahedral volume mesh as it gives smooth grid transition ( Fig. 2.3a). ...

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... hypermesh was generated using The ICEM CFD 17.2 for the geometry illustrated in Figure 2.2. For capturing surface details, "A patch dependent" method was used to create the 2D triangles surface mesh, and "Quick (Delauny)" method was used to generate the 3D tetrahedral volume mesh as it gives smooth grid transition ( Fig. 2.3a). In order to capture the near-wall boundary layer effects on the ground, inlet lip, and the engine nacelle model, an inflation was applied. This inflation method generated structured wedge elements also known as "Prism Layers" on these surfaces, which were smoothed as they transitioned to the surrounding tetrahedral elements. The ...

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... on these surfaces, which were smoothed as they transitioned to the surrounding tetrahedral elements. The method used was total thickness, with 25 inflation layers, and a growth rate of 1.1. Additionally, in order to accurately visualize the vortex core flow, a fine mesh was generated on the ground surface were the inlet vortex expected to form ( Fig. 2.3a), and "Volume Mesh Density" near the engine inlet was created to give more highly resolved mesh. ...

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... in the flow physics and sufficient time for the domain to adapt to these flow changes. Moreover, the steady-state results were used as the initial conditions for the transient solver. The results showed that, as the value of the crosswind speed increases, the intensity of the vortex increases and the static pressure on the ground decreases ( Fig. 2.6). Moreover, as the value of the static pressure on the ground decreases, the more suction force is produced, which leads to ingesting more foreign objects to the engine. ...

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... 0 = 9 í µí±š/í µí± í µí±’í µí± and an initial Angle í µí»¼ 0 = 30.82 í µí±‘í µí±’í µí±”. .1 shows that RK2 method took less time step (í µí»¥í µí±¡ = 0.01) to calculate particle trajectory than the Euler method (í µí»¥í µí±¡ = 0.001). Then the same particle trajectory was also calculated by RK4 numerical scheme and compared with RK2 solution ( Fig. 3.2). As shown in Figure 5.2, the RK2 and Rk4 gave the same trajectory with the same time step (í µí»¥í µí±¡ = 0.01). However, RK2 method takes less running time than RK4 method as it has less number of coefficients. As the result of this investigation, The Rk2 was chosen to calculate the sand particles trajectories in this study as it ...