Numerical and Experimental Investigations into the Characteristics of Wageningen B4-70 Series of Propeller with Boss Cap Fins

Abstract

Applying propeller boss cap fins (PBCF) in open B-series has been studied. PBCF is able to decrease the wake effect behind the propeller which can influence the propeller’s thrust and torque. Open propeller using PBCF is analyzed using computational fluid dynamics (CFD) which generate convergent result compared to experimental data. The solver is based on the Reynolds Averaged Navier Stokes Equation (RANSE) solutions and turbulence modeling explicit algebraic stress model (EASM). The test data was obtained from CFD simulations consisting of the open propeller and PBCF despite the experiment was done to PBCF only. All measurements were carried out from J = 0 to J = 1.0 with speeds from 0 m/s to 2.445 m/s.The results of the investigation on the B4-70 propeller with Boss cap fins convergent showed thought-provoking phenomena both on CFD and experimental work. Test results at The B4-70 Propeller without using PBCF high Pressure at J = 0.1 - 0.9, but with boss cap fins can reduce pressure at high-speed J = 0.9, so further research is needed to low-speed J = 0.1 - 0.5; Then visualization of velocity on propeller B4-70 without PBCF shows an increase in flow velocity in the boss cap fins when J = 0 to J = 0.9. The induced axial velocity in the blade propeller is the same and propeller B4-70 with PBCF decreases in speed in the boss cap fins when J = 0 to J = 0.9. However, the induce axial velocity in the blade propeller is the same. Convergent PBCF can reduce the return flow velocity in the boss cap propeller area, inversely proportional to the open propeller. Comparison of open propeller and PBCF shows that using PBCF there is an increase in the KT value at high speed of 10% to24% and a decrease in the 10KQ value on PBCF from J = 0.8 to J = 1.0 of 7% to 14%, but η_0 value at J = 0.8 to J = 1.0 increased by 3% to 8%. This Explained that the use of PBCF when the higher the value of J, greater the increase in η_0 value. Mainly, B4-70 propeller with PBCF with a converging boss cap shape with 15-degree slope exhibits increased efficiency.