Simulating hydrodynamics can require extensive calculations which becomes a problem when doing interactive simulations. This thesis investigates an efficient method for hydrodynamic simulations with the effects of buoyancy, drag, lift and added mass that is implementedand tested with the help of AgX Dynamics using triangulated meshes. For buoyancy, drag and lift a method of numerical integration over triangles was used to calculate the forces and torques acting on each triangle of a mesh. For added mass a large part of the calculations could be done before the simulation starts using a Boundary Element Method (BEM). The final value for the added mass was calculated each time step based on how the object was submerged. The method of triangle integration produced results that were close to the analytical values with a certain mesh dependence. The results had an increasing accuracy when the mesh had a more exact representation of the object. The drag and lift coefficients could however be better adjusted. The added mass results also had a mesh dependence, but with accuracy increasing with number of triangles even for shapes that already had an exact representation, e.g. a cube. For a fully submerged sphere with 4900 triangles the maximum error for the added mass was 0.65%. The time required for precalculations using BEM had a rapid growth with increasing number of triangles due to the factorization of a dense matrix that has a complexity of O(n3). For the hydrodynamic calculations done each time step the time requirement increased linearly with number of triangles.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:umu-90060 |
| Date | January 2014 |
| Creators | Ålstig Sandberg, Sandra |
| Publisher | Umeå universitet, Institutionen för fysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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