The Watertight Propeller Dynamometer of high capacity is sealed against pressure of up to 1 bar above atmospheric pressure and against relatively high vacuum (1 bar = 10 to the power 5 N/m2 = 0.1 MPa). Idle friction of the measuring shaft is small despite the use of sealing rings and is approximately 0.3 Nm for dynamometer and 0.4 Nm for dynamometer. The dynamometer can be used also for propulsion tests with relatively high torque and thrust values in ship models under water. That has slightly larger dimensions, but is of similar appearance. It is thus suitable for use in the measuring section of cavitation tunnels, as an inner drive dynamometer in ship models or in dummy bodies mounted in the measuring section of a cavitation tunnel.
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A variety of dynamometers can be supplied for use with the educational carriages, these are interfaced with he support frame for connection to ship models or fitting of propeller models. These include:
Educational Multi Component Ship / Yacht Model Balance
Educational Ship Stability Dynamometer
Educational Self Propulsion
Traditional Self-Propulsion Dynamometer for educational scaled models
Educational Resistance Dynamometer
Educational Open Water Propeller / Turbine Dynamometer.
The necessity to support the international ship model testing community with the provision of a Podded Propeller Dynamometer has therefore become imperative the need to carry out tests to establish the hydrodynamic and operational advantages of podded drives over conventional propulsion systems is a worldwide requirement and urgent. A variety of podded propulsion drive systems are increasingly being introduced into current and future generation designs of cruise liners, ferries, vessels operating in ice conditions, shuttle tankers and specialist multi-hull vessels.
Features:
The use of a single propeller fitted at either end of the pod or a duel propeller combination rotating in the same direction. The standard gearbox suitable for a Maximum Torque for two propellers 15Nm at each shaft with a combined torque of 30Nm or a single propeller with a max torque of 30Nm
Torque and thrust strain bridge sensor telemetry units available for each propeller (single supplied as standard);
A compact podded propeller dynamometer with driveshaft, bevel gears and two output shafts to which propellers can be fitted if required. Please note the propeller shafts can be designed to suit customers requirements, however in view of the high forces generated within the unit,there is a requirement to use low-mass propellers and not to exceed recommended limits;
Height and Angle Mechanisms: these can be supplied with frame suitable for use in a towing carriage or a mounting system designed to fit the equipment for use with in a cavitation tunnel allowing adjustment in height/depth as well as adjustment in Roll, Yaw and Pitch Angles.
Drive motor and control with speed output signal for data acquisition if required
Combined with an three component balance facilitating measurement of forces drag/unit thrust Fx or lateral force Fly as well as Yaw moment Mz in open water testing
Speed Display Rack: this can be used either with the inline encoder or drive output to display the propeller speed or drive speed.Please note that as the uses a 2:1 gearbox.
The Contra Rotating Propeller Multi Purpose Propulsion Dynamometer is a generic design for use either within a large Cavitation Tunnel or within underwater models in the Towing Carriage. The design greatly simplifies the transmission of power to the output shafts and reduces the number of moving parts (and thus generated noise) considerably. In this case is to be supplied for use in both facilities with the appropriate equipment and accessories including a separate water cooling system for the integral motors. The new CRP dynamometer is based on the Dynamometer principle of integral motors in the gondola, however with higher ratings to meet our customers requirements.
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The dynamometers have been designed for low friction torque at the propeller shaft and for this reason shaft seals are not fitted. As a result, the dynamometers are not watertight. If watertight propeller dynamometers are required, alternative designs are available. All dynamometers have a similar appearance although vary in size / rating to suit the intended specification required. The Dynamometers are compact with low weight and small dimensions and as such are suitable for use with models over a wide range of sizes however also offer with suitable accessories the ability of mounting two dynamometers driven through a gear box to allow the testing of twin screw models. The self propulsion dynamometer measures thrust and torque of the propellers during propulsion tests with ship models on smooth water and in waves in towing tanks.
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This additional sealing equipment can be taken out easily and can be replaced by the sealing arrangement for use in ship models in the towing tank in order to reduce friction So if the additional equipment for use of the dynamometers in a cavitation tunnel is ordered, the dynamometers are also suitable for use in ship models in a towing tank. In the first case, they are provided only with a sealing arrangement suitable for sealing against water pressure whereas in the latter case, they are supplied with additional equipment that seals the propeller dynamometers against relatively high vacuum and against pressure up to 1 bar above atmospheric pressure.
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The propeller dynamometers are new designs to replace earlier dynamometers only adjustments to the inclination of the propeller shaft could be made, but with the introduction of the adjustment of propeller shaft height can also be achieved. Depending on the maximum capacity of the drive motors, the maximum torque ratings, and consequently the diameters of the propeller shaft ends, are different. The capacity of the drive motors of the same whereas that of less. Apart from the different arrangement possibilities,the technical details of all essential parts of propeller dynamometers are identical, with exception of the capacity of the drive motors and the maximum load ratings in respect of measurement of torque and thrust.
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Equipment is designed for the measurement of resistance and alteration of draught and trim during tests with relatively small ship models on smooth water and in waves.
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The dynamometers can be supplied with the standard height of the vertical streamlined profile or with an increased height of the vertical streamlined profile as described below. The three dynamometers are of the same general type but differ in size and capacity as shown below. Full technical details of the dynamometers are provided below.
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It is therefore possible to control the speed of the forward and the rear dynamometer independently from each other. All 3 CRP dynamometer types have separate driveshafts for the forward and rear dynamometer to facilitate the connection of two motors. Alternatively, the two driveshafts can be connected through a gearbox normally with a transmission ratio of1:1 so that it is possible to drive both the forward and the rear dynamometerat the same speed in opposite directions, from one motor.
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Resistance dynamometers combined with model clamp are of the same general type, but with different capacity. They are also used during propulsion tests with ship models for applying force in addition to the propeller thrust, which is often necessary for the test program. They are designed for the measurement of resistance of ship models, which are towed by a towing carriage.
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The Turbine Dynamometer and itsinstrumentation then measures and displays the speed, torque and shaft poweravailable at the dynamometer. The Turbine Dynamometer instrumentation fitsabove the dynamometer, in the iInstrument frame of the Centrifugal Pump Module. You need the Turbine Dynamometer for tests on the optionalturbines. You connect the outlet of the centrifugal pump to your turbine. As the pumpforces water through the turbine, you use a control on the Turbine Dynamometerto adjust a band brake. It fits on the Centrifugal Pump Module, near the outlet end of thecentrifugal pump. You fit any of the three optional turbines to the Turbine Dynamometer. Each turbine has a brake drum that fits inside the dynamometer. This loads the turbine.
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Cylinder Dynamometer
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Disk dynamometer, the diameter of 10cm, with zero device specifications are as follows:
1 N scale: 0.1N
2N scale: 0.2N
5N scale: 0.1N.
It is made up of suspension hook, spring dynamometer, triangle tab, pointer, dial plate, rod, plate spacing.
Meassuring range: 0-5N.
The unit consists of four different types of pumps namely-centrifugal, turbine, reciprocating and axial flow pump, a common storage tank, and measuring instruments. Each pump is driven by a motor dynamometer for measuring TRUE pump input power. Multi Pump Test Set, Motor Dynamometer is a self contained set for studying the characteristics for various types of pumps. Speed control is by an inverter. The unit is floor standing with removeable supports. By manipulating flow control valves and a selector switch, each pump can be operated individually.
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The unit consists of a storage tank and a centrifugal pump with a motor dynamometer on a steel base for measurement of TRUE pump input power, and measuring instruments. Mini Centrifugal Pump Test Set Motor Dynamometer is a self contained bench top unit for studying the centrifugal pump characteristics. Speed control is by an inverter.
Experiments:
Pump input, output and true efficiency at various speeds.
Flow rate vs head at various speeds.
0N?2N?The product is composed of a spring, a pointer, a scale plate, a pull rod, a suspension device, a clamping handle and a pointer adjustment device, etc., indicating that the value tolerance range is not more than 0.1N, and the return to zero tolerance is not more than 0.05N.
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A precision-machined base plate holds the motor and its sensors. The Universal Dynamometer directly drives the Fluid Power machines. This means that the user has no need to fit or adjust the tension of belts and pulleys. The coupling between the Universal Dynamometer and all Fluid Power machines is a jaw-type coupling with a rubber element. The base plate has location points to give accurate and repeatable alignment onto each Fluid Power module.
The front of the motor drive and display unit has motor stop, start and speed controls. Outlets on the back of the unit give power for instruments supplied with the Fluid Power modules. The motor drive and display unit contains a variable-speed a.c. inverter drive and includes signal conditioning. It digitally displays speed, torque and shaft power. This reduces the need for multiple mains connections and gives a neater and safer equipment arrangement. The unit fits on the instrument frame fitted to all the Fluid Power modules.
