N  E  W  S   L  E  T  T  E  R


High Pressure Compressor Stators Variable Geometry Actuation System Test Facility

The Gas Turbine Research Establishment (GTRE), Bangalore, has developedVGA actuation system test facility a High Pressure Compressor Stators Variable Geometry Actuation System Test Facility. This test rig has been designed to house the compressor casing with complete variable geometry (VG) mechanism consisting of linkages and dummy blades with cams that can move against flat springs to simulate the aerodynamic loads.

A control system is required to operate the VG stators of the Kaveri engine high pressure compressor spool. This effects the changes in the stagger angles of the inlet guide vanes (IGV), the first and second stage stator blades of the HP compressor which is based on a schedule related to the spool speed.

The VG mechanism transforms linear motion of the actuator to rotary motion of the guide vanes and stator blades of the compressor. The VG control system consists of electronic control units, servo valves, actuators, and sensors, etc to achieve a desired actuator position through a fluid powerpack with aviation fuel as operating medium. The rig is being used for testing the performance of the control system under simulated aerodynamic loads.

Snow and Meteorological Observatory in Gangotri Glacier

The Snow & Avalanche Study Establishment (SASE), Chandigarh, has opened a new area in snow and meteorological research in Gangotri glacier. DRDO in collaboration with the Department of Science & Technology (DST) has taken up this task for establishment and operation of meteorological observatories in the Gangotri glacier to provide continuous online data on real-time basis to the organizations participating in the glaciology programme of Gangotri glacier.

An overview of automatic weather station at BhojbasaSASE has since completed installation of full-fledged snow and meteorological station near Gangotri glacier. The observatory is located near the snout of Gangotri glacier (Gaumukh), called Bhojbasa, base camp at an altitude of 3800 m asl. Bhojbasa is located 18 km ahead of Gangotri village in Garhwal district of Uttar Pradesh. The observatory consists of a manual observatory and an automatic weather station (AWS). This experimental setup will provide continuous snow-met data, which includes atmospheric parameters viz., wind speed and direction, temperature, humidity, pressure, albedo and snow. The data is collected round the year. The VHF radio communication has been established between the observatory and Research & Development Centre (RDC), SASE. This communication channel is used for receiving manually collected data from the observatory. A proper satellite (INSAT-IIB) link between AWS and the Earth Receiving Station (ERS), which is located at SASE has been established and online continuous data is being archived from the Gangotri glacier since 10 January 2000. Two pre-fabricated shelters have also been erected at Bhojbasa observatory for housing the instruments and for accommodation of technical/scientific personnel deployed at the field observatory. Establishment of the above is helping SASE in tracking the weather systems from North-West Himalaya to Central Himalaya. In future, two additional AWS, one in accumulation zone and the other at the equilibrium line are being planned. The data collected from this location is being transferred to the data bank of DST for research.