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

Document Type : Article


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


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.


Main Subjects

1. Pantelatos, D.K. and Mathioulakis, D.S. Experimental  ow 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-ow  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 ow", AIAA  Journal, 25, pp. 550{559 (1987).  7. Groves, N.C., Huang, T.T., and Chang, M.S. Geometric  characteristics of DARPA subo_ models:  (DTRC Model Nos. 5470 and 5471)", Report David  Taylor Research Center (1989).  8. Huang, T. and Liu, H. Measurements of ows 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 pro_les 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. E_ects of bulbous bow on cross-ow  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 e_ect on the visualized ow  _eld 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 con_gurations 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).  A. Saeidinezhad et al./Scientia Iranica, Transactions B: Mechanical Engineering 27 (2020) 1277{1289 1289  15. Akbarzadeh, P., Molana, P., and Badri, M.A. Determining  resistance coe_cient for series 60 vessels  using numerical and experimental modelling", Ships  and O_shore Structures, pp. 1{6 (2015).  16. Ram, B.R.R., Surendran, S., and Lee, S. Computer  and experimental simulations on the _n e_ect on ship  resistance", Ships and O_shore Structures, 10, pp.  122{131 (2015).  17. Park, J.Y., Kim, N., and Shin, Y.K. Experimental  study on hydrodynamic coe_cients 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 submarine 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. Inuence 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 coe  _cients using system identi_cation 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 e_ect 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 Cor_eld, 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-ow separation  on an ellipsoidal body during constant yaw turns and a  pitch-up maneuver with roll oscillation", PhD Thesis,  Virginia Tech. (2010).