Potential Flow Evaluation of the Interference Effect of Strut-Through- Appendage-Tip Model Mounting Technique and Reduction of the Effect Using Blowing and Suction
Abstract
A parametric study based on incompressible, irrotational flow theory was conducted to evaluate the effect of strut support interference on the flow field about a model. The use of suction and blowing to correct the support interference is also investigated. Two struts were considered for numerical analysis, a small chord strut of constant cross section and a large chord strut of varying cross section, both attached to the tip of a model submarine sail. For the present study the SS N21 class and SSN 688 class sail geometries are utilized. To assess the level of strut interference, the presence fields on the surface of the sail and a flat representation of the hull were evaluated as follows. The flow field was computed for the model geometry without a strut attached (baseline configuration) and the results are compared with identical calculations for the model-strut combination. The calculated results are presented graphically as contour plots of the pressure coefficient (Cp). Contour plots of delta p (the difference between baseline ad sail-strut results) are utilized to identify regions of principal strut interference. Finally, suction and blowing was applied to minimize strut interference in areas considered important to hull boundary layer and sail flow that would affect wake measurements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1988
- Accession Number
- ADA202424
Entities
People
- David W. Coder
- Robert W. Mellish