Boundary layer and surface pressure distribution behavior over a submarine nose model with two different nose shapes

Document Type : Article

Authors

1 Department of Mechanical Engineering, Yazd University, Daneshgah Boulevard, Safaeiyeh, Yazd, P.O. Box 89195-741, Iran

2 Department of Mechanical and Aerospace Engineering, Malek Ashtar University of Technology, Esfahan, P.O. Box 83145-115, Iran

Abstract

Surface pressure distributions and boundary layer profiles are measured over the nose surface of a submarine model in a wind tunnel. The tests are conducted for two different nose shapes in order to study the effects of nose shape on the flow field around the model. The influence of Reynolds numbers, which are 0.5×106, 0.8×106 and 106, and pitch angles, α = 0, 5, 10 and 15°, on the surface pressure distribution over the surface of two nose shapes are investigated. Furthermore, the effect of the longitudinal pressure gradient on the boundary layer velocity profiles and the probability of the separation in the plane of symmetry of the nose are studied. It is found that the Reynolds number does not have a significant influence on the nose surface pressure distribution at all pitch angles. The results show that the presence of the adverse pressure gradient in major portion of the blunter nose shape causes the non-dimensional velocity profiles of boundary layer in locations of 0.1≤X/L≤0.23 are deviated from the log layer profile. Therefore the separation on the blunter nose shape is more likely than the other nose at high pitch angle manoeuvres.

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References:
1. Pantelatos, D.K. and Mathioulakis, D.S. "Experimental flow study over a blunt-nosed axisymmetric body at incidence", Journal of Fluids and Structures, 19, pp. 1103-1115 (2004).
2. Paster, D., Importance of Hydrodynamic Considerations for Underwater Vehicle Design, 86th OCEANS, Washington, DC, USA (1986).
3. Saeidinezhad, A., Dehghan, A., and Manshadi, M.D. "Experimental investigation of hydrodynamic characteristics of a submersible vehicle model with a nonaxisymmetric nose in pitch maneuver", Ocean Engineering, 100, pp. 26-34 (2015).
4. Patel, V., Nakayama, A., and Damian, R. "Measurements in the thick axisymmetric turbulent boundary layer near the tail of a body of revolution", Journal of Fluid Mechanics, 63, pp. 345-367 (1974).
5. Ramaprian, B., Patel, V., and Choi, D. "Mean-flow measurements in the three-dimensional boundary layer over a body of revolution at incidence", Journal of Fluid Mechanics, 103, pp. 479-504 (1981).
6. Patel, V. and Baek, J. "Boundary layers in planes of symmetry. I-Experiments in turbulent flow", AIAA Journal, 25, pp. 550-559 (1987).
7. Groves, N.C., Huang, T.T., and Chang, M.S. "Geometric characteristics of DARPA suboff models: (DTRC Model Nos. 5470 and 5471)", Report David Taylor Research Center (1989).
8. Huang, T. and Liu, H. "Measurements of flows over an axisymmetric body with various appendages in a wind tunnel: the DARPA SUBOFF experimental program", 19th Symposium on Naval Hydrodynamics, Seoul, Korea (1994).
9. Javadi, M., Manshadi, M.D., Kheradmand, S., and Moonesun, M. "Experimental investigation of the effect of bow profiles on resistance of an underwater vehicle in free surface motion", Journal of Marine Science and Application, 14, pp. 53-60 (2015).
10. Abedi, S., Dehghan, A.A., Saeidinezhad, A., and Manshadi, M.D. "Effects of bulbous bow on cross-flow vortex structures around a streamlined submersible body at intermediate pitch maneuver: A numerical investigation", Journal of Marine Science and Application, 15, pp. 8-15 (2016).
11. Saeidinezhad, A., Dehghan, A.A., and Dehghan Manshadi, M. "Nose shape effect on the visualized flow field around an axisymmetric body of revolution at incidence", Journal of Visualization, 18, pp. 1-11 (2014).
12. Roddy, R.F. "Investigation of the stability and control characteristics of several configurations of the DARPA SUBOFF model (DTRC Model 5470) from captivemodel experiments", Report David Taylor Research Center (1998).
13. Van Randwijck, E.F. and Feldman, J.P. "Results of experiments with a segmented model to investigate the distribution of the hydrodynamic forces and moments on a streamlined body of revolution at an angle of attack or with a pitching angular velocity", DTIC report document (2000).
14. Zhang, S., Li, H., Pang, Y., Chen, Q., and Yan, P. "Experimental investigation on roll stability of blunt-nose submarine in buoyantly rising maneuvers", Applied Ocean Research, 81, pp. 34-46 (2018).
15. Akbarzadeh, P., Molana, P., and Badri, M.A. "Determining resistance coefficient for series 60 vessels using numerical and experimental modelling", Ships and Offshore Structures, pp. 1-6 (2015).
16. Ram, B.R.R., Surendran, S., and Lee, S. "Computer and experimental simulations on the fin effect on ship resistance", Ships and Offshore Structures, 10, pp. 122-131 (2015).
17. Park, J.Y., Kim, N., and Shin, Y.K. "Experimental study on hydrodynamic coefficients for high-incidenceangle maneuver of a submarine", International Journal of Naval Architecture and Ocean Engineering, 9, pp. 100-113 (2017).
18. Watt, G., Nguyen, V., Cooper, K., and Tanguay, B. "Wind tunnel investigations of submarin  hydrodynamics. The development of the DREA static test rig and some results", Can. Aeronaut. Space J./J. Aeronaut. Spat. Can., 39, pp. 119-126 (1993).
19. Altosole, M. and Francescutto, A. "Influence of sea state models on calculated naval vessel stress spectra", Report Defence Research and Development Canada (2015).
20. Hajizadeh, S., Seif, M.S., and Mehdigholi, H. "Determination of ship maneuvering hydrodynamic coefficients using system identification technique based on free-running model test", Scientia Iranica, 23, pp. 2154-2165 (2016).
21. Javanmardi, M., Binns, J.R., Thomas, G.A., and Renilson, M.R. "An investigation into the effect of pressure source parameters and water depth on the wake wash wave generated by moving pressure source", Scientia Iranica, 25, pp. 2162-2174 (2018).
22. Barlow, J.B., Rae, W.H., and Pope, A., Low-speed wind Tunnel Testing, In John Wiley and Sons, 3th Ed. (1999).
23. Hosder, S. and Simpson, R.L. "Unsteady skin-friction measurements on a maneuvering DARPA2 SUBOFF model", Virginia Polytechnic, Report No. VPI-AOE- 272 (2001).
24. White, F.M. and Corfield, I., Viscous Fluid Flow, 3, McGraw-Hill New York (1991).
25. Spalding, D. "A single formula for the, law of the wall", Journal of Applied Mechanics, 28, pp. 455-458 (1961).
26. DeMoss, J.A. "Skin friction and cross-flow separation on an ellipsoidal body during constant yaw turns and a pitch-up maneuver with roll oscillation", PhD Thesis, Virginia Tech. (2010).