Vol . 8 No. 5 & 6 October/December 2000
To pursue R&D activities in the field of naval technology, the requirement of sophisticated infrastructural facilities and test set-up needs no emphasis. Over the years, due to progressive planning, DRDO has created several facilities to enable scientists to progress research programmes. This being a continuous, time and fund consuming process, the creation of needed facilities is embedded in the five year plans of DRDO with an aim to attain self-sufficiency in the years to come. Certain special facilities available with the naval group of DRDO labs are highlighted here.
Hydrodynamic Test Facilities
The first and the foremost of such special facilities are hydrodynamic test facilities consisting of towing tanks, cavitation tunnel, wind tunnel, etc., established to carry out model tests to determine the performance characteristics of naval platforms and submerged vehicles.
High Speed Towing Tank
A high speed towing tank (HSTT)
with a cross- section of 8 x 8 m and 500 m length has been established, which is equipped
with a high speed towing carriage to tow models up to 20 m/s. Random seas can be generated
using a computer-controlled dual flap wave generator in the tank to test the performance
of surface ship models in different sea-state conditions. The planar motion mechanisms
(vertical and horizontal) can, to some extent, test the models for their manoeuvrability.
The HSTT is also equipped with a workshop to make exact scaled down models with all
The naval platform, the equipment and the machinery all are subjected to severe shock
loading due to underwater explosions
or a direct hit to the platform by underwater weapons/other weapons. In such conditions
also, the onboard machinery and equipment should function reliably to take the platform
out of the danger zone and revert to its original operational condition. It is therefore
essential to subject the machinery and equipment for the shock withstandability. A shock
testing tank with a cross-section of 15 x 12 x 10 m which is a double-walled construction
along with a floating shock platform is being extensively used to carry out the shock
testing of equipment. The field shock testing platforms and an instrumented vehicle are
used in combination for testing and analysis of data in field conditions. The performance
of equipment and machinery can also be studied using vibration
The cavitation tunnel, with a test section of 1 x1 x 6 m, can test the performance characteristics of propellers and underwater bodies. This facility can generate cavitation numbers 0.03 + 10/V .
A wind tunnel is a part of these hydrodynamic test facilities. All these facilities are useful to carry out the open water tests, self-propulsion tests, drag tests, forces and moment measurements, self noise measurements, pressure diffusion, wake surveys, flow/cavitation visualisation, etc.
The understanding of ocean behaviour is essential for the design of underwater sensors.
DRDO has therefore designed and constructed a multipurpose marine
acoustic research ship, Sagardhwani. The ship is equipped with 10 modern laboratory
facilities, sophisticated sensors and state-of-the-art handling gears. The data collection
is a continuous process based on annual mission plans drawn. It generates a vast database
and analysis reports in the form of atlases published regularly to
There is a lake facility called underwater acoustic research facility (UARF) with three watercrafts. An 80 ton barge, a floating platform that can take the transducers up to 4 m in diameter and 10 ton in weight in a central well and a boat are part of this facility, which can provide water . depths of more than 100 m. It caters for acoustic measurements on large arrays or at low frequencies. Beam forming measurements can be carried out at UARF.
For underwater electroacoustic measurements and sonar transducer calibration, highly sophisticated facilities of international standards have been established. There is an open water tank with moving trolleys and a transducer positioning system and a set of sophisticated instrumentation.
Materials and Transducers Simulated test facility (MATS) is the only one of its kind in the Asia-Pacific region and one of the very few in the entire world. MATS provide three pressure chambers for underwater measurements on materials and transducers. Static and dynamic measurements can be carried out under different conditions of temperature and pressure simulating ocean depths. The maximum operating pressure of 70 kg/cm2 and minimum temperature of -20oC can be achieved in this facility. The pneumatically-controlled vibration isolation systems provide an excellent isolation from ground related or structure related disturbances in all three axes.