Investigations of Scaling Effects on Submarine Propeller and Stern Boundary Layer Flows
Abstract
The simulation of flows past ships poses a particular challenge because of the size of the ship and the resulting large values of dimensionless parameters such as Reynolds number. As a result, the only simulation method that can duplicate the required parameters is computational fluid dynamics (CFD). However, the drawback of CFD at these large scales is the lack of data available for validation of the CFD solutions. To provide some insight into this problem, experimental measurements were made on a small-scale model and a large-scale model. The small-scale model was 0.286 m (0.940 ft) long and was tested in a water tunnel facility located at Mississippi State University. A method of obtaining drag values from wake profile measurements was developed and the measurements were made using a laser Doppler velocimeter (LDV) system. The large-scale model was 7.03 m (23.0 ft) long and was tested in the U. S. Navy William B. Morgan Large Cavitation Channel (LCC). Computational simulations of the flows at both of these scales were obtained to see bow well the solutions agreed with the experimental results over a very large change in length scale. This was of particular interest since the factor of the increase in length scale in going from the LCC model to the lull-scale prototype is approximately the same as the factor of the increase in length scale between the small-scale and large-scale models. The drag coefficients of both models were measured. The thrust coefficients for a propeller on the large-scale model were measured over a range of advance ratio. The drag coefficients for both models and the propeller thrust coefficients for the large-scale model were obtained from the computational simulations. The experimental and CFD drag coefficients were in reasonable agreement for the small-scale model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2004
- Accession Number
- ADA427002
Entities
People
- Allison C. Cash
- David H. Bridges
- James W. Bagley
- John L. Freudenthal
Organizations
- Mississippi State University