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Case 2.7



Hino, T., (2005 ed.), “Proceedings of CFD Workshop Tokyo 2005”, NMRI report 2005

Requested computations:

The self propulsion computation is to be carried out at the ship point following the experimental procedure. Thus, the rate of revolutions of the propeller \(n\) is to be adjusted to obtain force equilibrium in the longitudinal direction considering the applied towing force (Skin Friction Correction, SFC): \(T = R_{T(SP)}-SFC\)
Where \(T\) is the computed thrust, \(R_{T(SP)}\) is the total resistance at self propulsion and SFC = 30.3[N] (from the test).
In case this procedure cannot be carried out, set \(n\) to the measured value \(9.5\)[rps].

Table/Figure# Items EFD Data Submission Instruction
Data file Image Image files Sample + Tecplot layout file
2.7-1 Axial velocity contours and cross flow vectors downstream of propeller plane
U_prop_EFD.dat prop_contour_EFD.jpg
\(-0.04 \le y/L_{PP} \le 0.04 \)
\(-0.055 \le z/L_{PP} \le 0.005\)
Contours level:
\(0 \le u/U \le 1.2\),
\(\Delta (u/U) = 0.1\), #levels=13
Line style: solid lines
Refer to EFD image
\(-0.04 \le y/L_{PP} \le 0.04 \)
\(-0.055 \le z/L_{PP} \le 0.005\)
Reference vector: magnitude 0.2
Refer to EFD image
2.7-2 Velocity downstream of propeller plane
(\(x/L_{PP}=0.9911\)) at \(z/L_{PP}=-0.03\)
uvw_prop_EFD.dat Refer to sample file for details Filename:
\(-0.03 \le y/L_{PP} \le 0.03\)
\(-0.5 \le u/U, v/U, w/U \le 1.2\)
Line style:
\(u/U\): CFD solid line; EFD open squares
\(v/U\): CFD dashed line; EFD open triangles
\(w/U\): CFD dotted line; EFD open circles
2.7-3 Hull surface pressure contours
( port side view )
Not yet available Cp_port_EFD.jpg Filename:
\(0.8 \le x/L_{PP} \le 1.05\)
\(-0.05 \le z/L_{PP} \le 0.01\)
Contours level:
\(-1.0 \le C_p \le 1.0\), \(C_p = \frac{p - p_{\infty}}{ \frac{1}{2} \rho U^2}\)
\(\Delta C_p=0.01\), #levels=201
Contours style:
Solid and dashed lines for positive (+) and negative (-) values, respectively.
Refer to EFD image

Note: a positive (+) sinkage value is defined upwards and a positive (+) trim value is defined bow up.

Submission Instructions:

All quantities are non-dimensionalized by denstiy of water (\(\rho\)), ship speed (\(U\)), and length between parpendiculars (\(L_{PP}\)): \begin{align*} F_r = \frac{U}{\sqrt{g \cdot L_{PP}}}, \quad R_e = \frac{U \cdot L_{PP}}{\nu} \end{align*} where \(g\) is the gravitational acceleration and \(\nu\) is the kinematic viscosity.