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FhSim
3.1.0
Marine systems simulation
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FhSim
3.1.0
Marine systems simulation
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Collaboration diagram for Propeller 4Q:\[ \tan{\beta} = \frac{V_a}{0.7 \pi n D} \]
\[ C_t = \frac{T}{\rho V_{r}^2 \pi D^2/8} \]
\[ C_q = \frac{Q}{\rho V_{r}^2 \pi D^3/8} \]
| Name | Width | Description |
|---|---|---|
| QuaternionNED | 4 |
The unit vector along the propeller thrust direction |
| RPM | 1 |
The rotational speed of the propeller in RPM |
| PD | 1 |
The current pitch/diameter ratio of the propeller |
| VelocityNED | 3 |
The linear velocity which the propeller travels through the water in north-east-down coordinates |
| PositionNED | 3 |
The position of the propeller in north-east-down coordinates |
| Name | Width | Description |
|---|---|---|
| BetaT | 1 |
The percentage of thrust loss due to ventilation [-] |
| BetaQ | 1 |
The percentage of torque loss due to ventilation [-] |
| Ct | 1 |
Currently used thrust coefficient |
| Cq | 1 |
Currently used torque coefficient |
| Us | 1 |
The propeller induced velocity on the water particle traveling through the propeller disk in m/s |
| Rs | 1 |
The radius of the propeller downstream jet in meters |
| BetaH | 1 |
Current hydrodynamic angle of attack |
| PD | 1 |
Current propeller PD value |
| ForceNED | 3 |
The force produced by the propeller in north-east-down coordinates |
| TorqueNED | 3 |
The torque produced by the propeller in north-east-down coordinates |
| ForceBody | 3 |
The force produced by the propeller in body coordinates |
| TorqueBody | 3 |
The torque produced by the propeller in body coordinates |
| ForceCorrectedNED | 3 |
The force produced by the propeller in north-east-down coordinates |
| TorqueCorrectedNED | 3 |
The torque produced by the propeller in north-east-down coordinates |
| ForceCorrectedBody | 3 |
Force corrected for loss effects in body frame |
| TorqueCorrectedBody | 3 |
The torque produced by the propeller in body coordinates |
| ShaftTorqueBody | 1 |
Shaft torque in body frame |
| ShaftTorqueCorrectedBody | 1 |
Shaft torque corrected for losses in body frame |
| ShaftPower | 1 |
Shaft power consumed |
| ShaftPowerCorrected | 1 |
Shaft power consumed corrected for losses |
| Name | Width | Description |
|---|---|---|
| D | 1 |
Propeller diameter |
| PropellerType | 1 |
Type op propeller(used for ventilation model) |
| WakeFraction | 1 |
Hull wake fraction w, default 0: the inflow velocity is (1 - w) times the free stream velocity along the shaft |
| ThrustDeduction | 1 |
Thrust deduction factor t, default 0: the effective thrust is (1 - t) times the propeller thrust (the deduction comes from the low pressure region the propeller generates on the hull) |
| PD | N |
Number of PD values in use |
| Ct \(0...N\) | M | Various thrust coefficients |
| Cq \(0...N\) | M | Various torque coefficients |
| ShaftPowerScaling | 1 |
Linear scale applied to shaft power output |
| PropellerThrustScaling | 1 |
Linear scale applied to thrust output |
| ReverseRotationDirection | 1 | Reverse rotation direction in visualization |
| AzimuthMainThrustLoss | 1 | If true the thrust loss from cross flow depends on the inflow angle (1 below 45 degrees, 0.8 above 90 degrees, and no loss when the surge speed is below 1 knot), and the torque has no loss; if false it depends on the body y velocity (the thrust factor falls to 0.2 and the torque factor to 0.75 at 7 knots of cross flow and above). Default false |
| Name | Width | Description |
|---|---|---|
| betaT | 1 | Ventilation state of the thrust. Initial value 1 |
| betaQ | 1 | Ventilation state of the torque. Initial value 1 |
| Vz_low | 1 | Axial flow state of the low speed propeller jet. Initial value 0 |
| Vz_high | 1 | Axial flow state of the high speed propeller jet. Initial value 0 |
| w1 | 1 | Rotational flow state. Initial value 0. Its derivative is set to 0 |
| w2 | 1 | Rotational flow state. Initial value 0. Its derivative is set to 0 |
| PropellerRotation | 1 | The rotation angle of the propeller (integral of RPM/60). Initial value 0. Only in a build with visualization |
[1] Volker Bertram, "Practical Ship Hydrodynamics", Butterworth and Heinemann, Oxford 2000 [2] Ralf Bachmayer, Louis L. Whitcomb and Mark A. Grosenbaugh, "An Accurate Four-Quadrant Nonlinear Dynamical Model for Marine Thrusters: Theory and Experimental Validation", IEEE Journal of Oceanic Engineering, Vol. 25, No. 1, January 2000
1.9.8