Open and ducted propeller virtual mass and damping coefficients by URANS-method in straight and oblique flow

Influence of skew on the added mass and damping characteristics of marine propellers

“…In general, the results obtained from the CLL model show agreement with the URANS predictions in Martio et al (2015) and results obtained from semi-empirical equations (Parsons et al, 1980;Schwanecke, 1963). The difference between the results from CLL and URANS method is due to the limitation of lifting line method.…”

“…10 together with URANS predictions in Martio et al (2015), as well as the semi-empirical equations developed by Parsons et al (1980) and Schwanecke (1963). Note that the URANS results presented in Martio et al (2015) only contain the components associated with surge and roll directions.…”

“…Recently, Martio et al (2015) calculated the added mass and damping coefficients of a moderately skewed propeller by imposing sinusoidal translational and rotational motion on a propeller using a 3-D unsteady Reynolds-averaged Navier-Stokes (URANS) solver, which showed good agreement with semi-empirical equations presented in Schwanecke (1963). The results obtained from the URANS method showed that viscous effects are relatively small compared to the pressure effects on the added mass and damping of propellers.…”

“…This is expected as the added mass coefficients are dominated by pressure effects. The damping coefficients obtained using the CLL model account for radiation damping only, while the URANS method presented in Martio et al (2015) accounts for radiation and viscous damping. Note that the CLL is much more efficient than the URANS method, especially when used to calculate all the coefficients in added mass and damping matrices.…”

“…Influence of oscillation frequency ω and rotational frequency n on m f ,11 and m f ,44 for propeller 1374. n¼ 56.5 rad/s for URANS(Martio et al, 2015).…”