The objective of a Cussons MMC (Multi Motion Carriage) with integrated PMM (Planar Motion Mechanism) is to reproduce with high precision the horizontal motion of a ship-model being towed in a Towing Tank following a prescribed trajectory.
MMC (Multi Motion Carriage) for 37m wide tank and towing speed of 6m/s.
The objective of a MMC (Multi Motion Carriage) with integrated PMM is to reproduce with high precision the horizontal motion of a ship-model being towed in a Towing Tank following a prescribed trajectory. The collected force and moment data can then be used for deriving the coefficients used in the equations of motion, necessary for determining the manoeuvring characteristics of the ship-model. This provides the basis for superior predictions of the manoeuvring and course keeping qualities of surface ships and the evaluation and determination of design criteria, leading to the assessment of almost all aspects of ship manoeuvring.
MMC Specifications (Suitable for models up to length 4m):
(Design modifications to the following technical specifications may be considered, depending upon a clients particular requirements)
Max Speed of Travel – X Direction: 6.0 m/s
Reverse Speed in X Direction: >4.0 m/s
Acceleration – X Direction: 0.8 m/s2
Y- (Sway) movement amplitude: Up to 17 m
Φ -(Yaw) movement amplitude: up to 90 degrees
Max. Speed for the Yo-movement: 4.0 m/s
Max. Acceleration for the Yo-movement: 1.0 m/s2
Max. Speed for the Φ -(Yaw) movement: 30 degrees/sec
Speed Accuracy (X, Y and Optional Δx): <0.1 % of set speed
Acceleration Y Direction: 0.8 m/s2
Max Emergency-stop Deceleration: 3.0 m/s2
Max Speed of Travel Δx Surge Carriage: 1.5 m/sec
Δx Surge movement travel: 1.5m
X Movement in longitudinal direction of the tank
Y Movement in transverse direction
Φ Angles around the vertical axis of the ship model
The MMC consists of a Planar Motion Mechanism (PMM) integrated onto a separate self-propelled Towing Carriage, with computer controlled servo motor operated mechanisms for producing longitudinal, transversal and rotating motions in a connected ship-model. These combined motions are superimposed on the normal motion of the MMC as it travels along the tank.
The ship-model is attached to the PMM by way of a telescopic tow post and multi-component balance that allows free heave and trim motion along with free and forced roll. Software controls the functioning of the PMM, monitors the model movement, acquires data and carries out evaluations of the model tests. The PMM can produce sinusoidal motion of surge, sway, yaw and roll plus combinations of all motions. The ship-model is free to rise, fall and trim, and is towed in a predetermined curvilinear path at predetermined speeds, whilst the resulting hydrodynamic forces and moments are measured as functions of time. This is especially useful for research purposes and for validation of CFD results, as well as for the direct determination of hydrodynamic coefficients of manoeuvring equations of motion.
The MMC consists of:
(Note: The standard supply of the MMC does not include main and current collector rails, which are charged separately depending on the length of tank)
The PC Based Control and Data Acquisition System provides the following capability:
The MMC (Multi Motion Carriage) is designed to carry out the following: