Turbomachinery Facilities
The turbocharger test stand is designed to investigate the compressors of small turbochargers. The turbine is driven by compressed air heated in a combustion chamber to an adjustable temperature.
The facility is also equipped with an independent oil supply system at variable pressure. Rotational speed is controlled by an optical system, mounted on the turbine. Maximum RPM depends on the test model. Mass flow at the compressor inlet is measured by means of an appropriate Venturi tube. A miniaturized probe carriage allows automatic flow traverses at the
diffuser exit. A microcomputer-controlled acquisition system equipped with scani-valves, pressure transducers and amplifiers makes it possible to measure more than 100 temperatures and static pressures on the shroud, diffuser walls and scroll. These measurements are available for on-line or off-line data reduction.
This facility is used for overall performance measurements and for more fundamental studies on scroll / vaneless diffuser interaction and active control of surge.
The VKI low speed turbine T-1 is an open-loop continuously operating facility. Air is supplied by a blower with a maximum capacity of 7 m3/s and 16 kPa pressure rise. The test rig is specially designed to study secondary flows in low aspect ratio bladings.
The set-up allows testing of isolated stators, single-stage turbines and 1½-stage turbines.
The inner shroud upstream of the first vane can be rotated by means of an independent drive in order to produce a skewed inlet endwall boundary layer. In the 1½-stage configuration both vanes are rotatable to allow change of their position with respect to each other. The maximum outer diameter is 780 mm. The power is absorbed by an electric generator. The instrumentation includes double-headed four-hole pressure probes, slanted hot wires and a light sheet technique for flow visualization. Measurements are recorded and processed on the central data acquisition computer.
The VKI R-4 test rig is a high speed compressor test bench with a closed loop system that can be pressurized from vacuum to 3 bars. This gives the possibility to modify independently the Reynolds number and then to test different operating conditions for an aero-engine (takeoff, cruise,...). The maximum shaft speed is 25 000 RPM. It has recently undergone a deep renovation phase mainly focused on a more efficient cooling system to stabilize the temperature even on high power regimes (500kW).
The VKI low-speed, single-stage compressor R-1 is used to study the behaviour of fluids in compressors and the effect of this behaviour on compressor operation and performance. The compressor has a rotor tip diameter of 700 mm with blades of 75 mm height.
The inlet and exhaust of the facility are atmospheric. The R-1 facility includes provision for measurement of pressure and velocity on the rotating rotor during full operation. Instantaneous pressures are measured using Kulite pressure transducers. Both velocity magnitude and direction near the blade surface are detected using thermal tuft, hot wire and V-shaped hot wire probes. Triple hot wire probes allow investigation of the velocity field in both absolute and relative frames of reference. Signals from these sensors are passed through a set of mercury slip rings to hot wire bridges.
When used in conjunction with measurements from stationary probes, rotating frame of reference measurements provide extensive information concerning mean and unsteady flow phenomena which occur during compressor operation.
