This project was performed on behalf of SINTEF Materials and Chemistry in close collaborationwith Lyng Drilling, part of the Schlumberger Group. The scope of the project has been todevelop a method for geometry and setup simplifications on a Computational Fluid Dynamics(CFD) simulation made on a drill bit at work; to see if there is a possibility to implement thistype of simulations as a step in the product development process of drill bits at the company LyngDrilling. This in order to establish the local flow-patterns around the drill bit, that governs amongother things how the cuttings is transported away and the cooling of the drill bit. The drill bitsoften have a pattern of surface erosion, caused by an increased intensity and velocity of the flowat that area. Zones with low flow velocity, stagnation points, can cause problems to the drillingas cuttings and mud can get stuck there subsequently leading to clogging of the drill head andincreased energy required for the overall drilling. The only success on simulating the mud flowaround the drill bit was obtained with transient simulations on a stationary drill bit. A rotatingcase was simulated with dynamic mesh, but simulation time was estimated to exceed 6 months,and this scenario was one of the limitations set initially in the project.No industrial gain can be obtained by implementing CFD-simulations as a step in the product development process for the design of drill bits at Lyng Drilling. The simulations are far too complex and require a lot of work and simulation time, as well as the parameter assumptions are too many.