CFD investigation on steady and unsteady performances of contra-rotating propellers

Abstract

The realistic flow on each blade of the front and rear propellers with contra-rotating propellers (CRPs) are most complex because that consist the interaction forces with themselves and it affects to the actual efficiency of the propeller blades. The wake of CRPs at the gap between the front and rear propellers have influent to the variation of propeller performance for the front and rear propellers. So, this paper presented the numerical simulation of propeller performance on CRPs with steady method in the first. Second, it is applied to evaluate the propeller performance with unsteady method in time accuracy including investigating the wake on a transverse plane between the front and rear propellers and a transverse plane located downstream of the rear propeller. The wake was analyzed through velocity vector magnitude contours. The numerical simulations were conducted using the Reynolds Averaged Navier-Stokes (RANS). The calculation results have been compared the measurement data.

Effect of geometrical features on the contra-rotating propeller hydrodynamic performances

“…Their boundary conditions are uniform velocity and static pressure respectively. The computational domain is radially limited by a cylindrical envelope of diameter 3.28D F as recommended by Kaewkhiaw (2018). The boundary condition applied to the outer wall is a symmetry condition.…”

“…Nouri et al (2018) optimized the CRPs propellers using the genetic algorithm with the Kringin method to determine the optimal radial pitch and camber distributions for both front and rear propellers. Kaewkhiaw (2018) conducted a numerical study based on the solution of RANS equations. The study evaluated hydrodynamic performance for both propellers of two CRPs models in steady and unsteady conditions.…”

Computational hydrodynamic analysis of a highly skewed marine propeller

“…For the steady case, flow equations are solved by adopting a rotating frame linked to the propeller and all blocks are also considered as rotary. In Fluent code, this procedure is called Moving Reference Frame (MRF) as reported by Kaewkhiaw (2018) and Kinaci et al (2018).…”