Instrumentation and Data Acquisition System For Large Scale Rotating Rig

Pratt & Whitney, USA of United Technologies Research Center (UTRC) designed the Large Scale Rotating Rig (LSRR) to perform experimental research with turbo machinery. After executing numerous aerodynamic research activities on compressor and turbine modules, the rig was transferred to National Aerospace Laboratories (NAL) under a collaborative project in the year 2004. The rig is now installed, commissioned and benchmarked at NAL. The rig currently incorporates a single stage reaction turbine module which was earlier used by Pratt & Whitney, USA to carry out few aerodynamic investigations. A sophisticated indigenous data acquisition system was designed and developed to aid the experimental tasks in the rig. It is a fully automatic PC based data acquisition system, incorporating hardware such as ZOC pressure scanners, individual pressure transducers, Scanivalve mechanical multiplexers, wafer switches, thermocouples, digital temperature scanner, DC motors, control actuators, dead weight testers and other accessories. The various hardware units are monitored and controlled by a GUI based software program developed using National Instruments Labview. The instrumentation and data acquisition system is designed to cater various requirements of the rig. These requirements include vane, blade, casing / hub platform surface pressure measurement, vane / blade exit wake flow measurement, temperature measurements and online calibration of pressure transducers

Aerodynamic Investigations on a Single Stage Turbine to Benchmark LSRR

The Large Scale Rotating Rig (LSRR) was transferred from Pratt and Whitney, USA to National Aerospace Laboratories (NAL), Bangalore, India on a collaborative project. The rig is now successfully installed and commissioned at NAL. The rig currently incorporates a single stage axial flow reaction turbine (a row of stator vanes and a row of rotor blades) which was earlier tested by Pratt & Whitney, USA at UTRC. A sophisticated indigenous data acquisition system was designed and developed to cater to the various experimental requirements of the rig such as vane, blade, casing, hub surface pressure measurement, vane / blade exit wake flow measurement, temperature measurements and online calibration of pressure transducers. In order to benchmark the rig, few experiments were carried out and the aerodynamic parameters of the vane and rotor were evaluated. The aerodynamic parameters such as total pressure coefficient and flow angles (past the vane and rotor) were evaluated. These parameters were determined by traversing five / three hole pressure probes in the wake flows. The measurements were made at three different radial locations past the vane and the rotor. The probe data were reduced using a multiple regression model that was earlier used by Pratt & Whitney, USA. The details of the rig, experimental methodology and a brief discussion of the results are provided in this report. The aerodynamic data from the benchmark experiments are also compared with that supplied by Pratt and Whitney, USA. As expected, the flow near the hub and tip region was highly complex due to the secondary flows