Document Type : Original Article


Sea-Based Energy Research Group, Babol Noshirvani University of Technology, Babol, Iran


Surface piercing propellers are special supercavitation propellers operating at free surface. These propellers are designed to have the best performance at the highest speed. The geometric parameters of the number of blades and the pitch ratio will significantly impact the critical advance coefficient range, ventilation and consequently the hydrodynamic performance of the propeller. Therefore, in this paper, the effect of two crucial parameters of pitch ratio and number of blades were experimentally studied in free surface water tunnel. After calibration and evaluation of uncertainty, two 5-bladed propellers with same section profile and pitch ratio of 1.5 and 1.4 used to investigate effect of pitch ratio. The results of two 5-blade and 6-blade propellers with same section profile and pitch ratio of 1.4 were compared. The immersion ratio was 40%, and the shaft inclination angle was zero. Results showed that increasing the pitch ratio increased the thrust and torque coefficients by 30%; while increasing the critical advance coefficient. Consequently that has led to the development of a full ventilation range and improved hydrodynamic performance of the propeller. In addition, by increasing the number of blades, at values greater than the critical advance coefficient, the thrust and torque coefficients were increased by 10%. However, the critical advanced coefficient changes were negligible. Comparing the results in the three-dimensional contours showed that with the change in the number of blades, by increasing the pitch ratio, the critical advance coefficient increased; which led to a further increase in efficiency.


Main Subjects

  1. Shiba, H., 1953. Air-Drawing of Marine Propellers. Report of transportation technical research institute, pp.91-320.
  2. Olofsson, N., 1996. Force and Flow Characteristics of a Partially Submerged Propeller. Chalmers University of Technology.
  3. Dyson, P.K., 2000. Modelling, Testing and Design of a Surface Piercing Propeller Drive. Retrieved from:
  4. Fernando, M., A. Scamardella, N. Bose, P. Liu and B. Veitch, 2002. Performance of a Family of Surface Piercing Propellers. Royal Institution of Naval Architects. Transactions. Part A. International Journal of Maritime Engineering, 144(Part A1), pp. 63-77. Retrieved from:
  5. Ferrando, M., S. Crotti and M. Viviani, 2007. Performance of Family of Surface Piercing Propellers, In Proceedings of the 2nd international conference on marine research and transportation (ICMRT’07). Ischia. pp. c63-c70.
  6. Peterson, D., 2005. Surface Piercing Propeller Performance. Naval Postgraduate School Monterey CA Department of Mechanical and Astronautical Engineering.
  7. Ghassemi, H., R. Shademani and A. Ardeshir, 2009. Hydrodynamic Characteristics of the Surface-Piercing Propeller for the Planing Craft. in International Conference on Offshore Mechanics and Arctic Engineering (Vol. 43444), pp. 589-595.
  8. Misra, S., R. Gokarn, O. Sha, C. Suryanarayana and R. Suresh, 2012. Development of a Four-Bladed Surface Piercing Propeller Series. Naval Engineers Journal, (124): 4.
  9. Yari, E. and H. Ghassemi, 2016. Numerical Study of Surface Tension Effect on the Hydrodynamic Modeling of the Partially Submerged Propeller's Blade Section. Journal of Mechanics, 32(5), pp. 653-664. Doi:
  10. Yari, E. and H. Ghassemi, 2016. Numerical Analysis of Surface Piercing Propeller in Unsteady Conditions and Cupped Effect on Ventilation Pattern of Blade Cross-Section. Journal of Marine Science and Technology, 21(3), pp. 501-516. Doi: 10.1007/s00773-016-0372-3
  11. Seyyedi, S.M., R. Shafaghat and M. Siavoshian, 2019. Experimental Study of Immersion Ratio and Shaft Inclination Angle in the Performance of a Surface-Piercing Propeller. Mechanical Sciences, 10(1), pp. 153-167. Doi:
  12. Rad, R.G., R. Shafaghat and R. Yousefi, 2019. Numerical Investigation of the Immersion Ratio Effects on Ventilation Phenomenon and Also the Performance of a Surface Piercing Propeller. Applied Ocean Research, 89, pp. 251-260. Doi:
  13. Javanmard, E., E. Yari, J.A. Mehr and S. Mansoorzadeh, 2019. Hydrodynamic Characteristic Curves and Behavior of Flow around a Surface-Piercing Propeller Using Computational Fluid Dynamics Based on Fvm. Ocean Engineering, 192, 106445. Doi:
  14. Alimirzazadeh, S., S.Z. Roshan and M.S. Seif, 2016. Unsteady Rans Simulation of a Surface Piercing Propeller in Oblique Flow. Applied Ocean Research, 56, pp.79-91. Doi:
  15. Javanmard, E., E. Yari and J.A. Mehr, 2020. Numerical Investigation on the Effect of Shaft Inclination Angle on Hydrodynamic Characteristics of a Surface-Piercing Propeller. Applied Ocean Research, 98, 102108. Doi:
  16. Seyyedi, S.M. and R. Shafaghat, 2020. A Review on the Surface-Piercing Propeller: Challenges and Opportunities. Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 234(4), pp. 743-770. Doi:
  17. Yousefi, A. and R. Shafaghat, 2020. Numerical Study of the Parameters Affecting the Formation and Growth of Ventilation in a Surface-Piercing Propeller. Applied Ocean Research, 104, 102360. Doi:
  18. Seyyedi, s.m. and R. Shafaghat, 2016. Design Algorithm of a Free Surface Water Tunnel to Test the Surface-Piercing Propellers (Spp); Case Study Water Tunnel of Babol Noshirvani University of Technology. International Journal of Maritime Technology, 6, pp.19-30. Doi: 10.18869/acadpub.ijmt.6.19