# Case 2.7

## Conditions:

• Same with G2010 case2.3a
• Self propelled at ship point in calm water
• Free (even keel)
• With propeller, without rudder
• $FR_{0}$
• $R_e = 1.40 \times 10^7$, $F_r = 0.26$$0$
• $L_{PP} = 7.27$$86$ [m], $U = 2.196$ [m/s]
• $\rho = 999.1$ [kg/m3], $\nu = 1.139 \times 10^{-6}$ [m2/s]
• $g = 9.81$ [m/s2]

## References:

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
($x/L_{PP}=0.9911$)
U_prop_EFD.dat prop_contour_EFD.jpg
prop_contour_EFD.lpk
Filename:
[Identifier]_prop_contour_2-7.jpg
Axis:
$-0.04 \le y/L_{PP} \le 0.04$
$-0.055 \le z/L_{PP} \le 0.005$
Contours level:
$0 \le u/U \le 1.2$,
$\Delta (u/U) = 0.1$, #levels=13
Line style: solid lines
Refer to EFD image
prop_vector_EFD.jpg
prop_vector_EFD.lpk
Filename:
[Identifier]_prop_vector_2-7.jpg
Axis:
$-0.04 \le y/L_{PP} \le 0.04$
$-0.055 \le z/L_{PP} \le 0.005$
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:
[Identifier]_uvw_prop_2-7.jpg
Axis:
$-0.03 \le y/L_{PP} \le 0.03$
$-0.5 \le u/U, v/U, w/U \le 1.2$
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
[Identifier]_uvw_prop_2-7.jpg
2.7-3 Hull surface pressure contours
( port side view )
Not yet available Cp_port_EFD.jpg Filename:
[Identifier]_Cp_port_2-7.jpg
Axis:
$0.8 \le x/L_{PP} \le 1.05$
$-0.05 \le z/L_{PP} \le 0.01$
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:

• [Identifier] should be [Institute Name]-[Solver Name]. For example, if your institute is NMRI and solver is SURFv7, identifier should be NMRI-SURFv7.
• Identifier in the Figure should be [Institute Name]/[Solver Name]. For example, if your institute is NMRI and solver is SURFv7, identifier should be NMRI/SURFv7.
• All figures should be in black and white.
• Authors may change the contour levels for turbulence quantities for better qualitative comparison.

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.