[Sovereignty]

I'm an undergraduate student who is undertaking a engineering group project on the design and analysis of a nuclear submarine. For our analysis, we decided to perform a CFD analysis on a full-size submarine (with appendages) operating underwater in a straight, horizontal direction, at a specific depth at 20-30 knots to determine the drag forces. We focused on drag force because it determines the size of the power requirements needed to drive the ship at its service speed. Our professor suggested to assume that the shape of the submarine is similar to existing submarines (at least approximately, so to use existing drag force data) to calculate our engine/thrust requirements in order to attain certain speeds and perform maneuvers accounting for drag and body forces.

We have access to Solidworks software to develop the geometry of the submarine model, but we only have the ANSYS Workbench V19.2 student version to work with for the pre-processsing (via ANSYS Mechanical?), solver manager (via FLUENT), and post-processing. Unfortunately, none of us have experience with CFD, but I've been taking time the past month to learn about governing equations for fluid flow, turbulence modeling associated with high Reynolds numbers, Navier-Stokes, fluid mechanics, and the boundary conditions. I've read a couple of research papers that are related to the type of CFD analysis we're looking to perform, but it seems like some of them focus on more complex calculations or different motions involved with the submarine models (i.e drift, angle of attack, rotational velocities, etc).

At this time, I am still unsure as to how to perform this type of CFD analysis. I'm aware that mesh generation, model setup, and numerical RANS-based solution (using ANSYS FLUENT) are all involved. I was wondering if anyone had any suggestions or advice as to how to setup, perform, and interpret this type of analysis using the ANSYS Workbench student software (Mechanical, FLUENT)?

I attempted to create a mesh of the submarine model, but I encountered a few errors in regards to the surface mesh and volume mesh and suggests to modify the mesh size (or geometry), but I'm not sure which one is the main problem. I attached a picture of the failed meshing attempt to visualize my problem.

Much Appreciated,

Jeff