We have a low static pressure fan test bed, enabling us to test the impact of disturbed flow at the fan inlet (low static pressure compressor) on its:

• efficiency,
• mechanical properties,
• vibrations,
• stable operation margin (stall margin).

The structure is designed to allow the introduction of virtually any disturbance at the inlet, whether axisymmetric or non-axisymmetric.

The test bed is set up vertically (axis of rotation perpendicular to the ground), the height of which is about 5 m and consists of an inlet lemniscate behind which the inlet duct is located. The single-stage fan is driven by an electric motor. Behind the fan section is an outlet duct enclosed by a throttle cone, which makes it possible to regulate the mass flow of air.

The desired velocity profile is achieved using a distortion screen with changeable porosity. The fan stator is made in 3D printing technology and can be easily replaced with another one (e.g. non-axisymmetric). The test bed is equipped with aerodynamic and aeromechanical sensors.

Fan tests – equipment

Aerodynamic instrumentation includes, but is not limited to, the following items:

• 5-holed pressure probes with a thermocouple (mounted on a rotating measuring ring) enabling the measurement of flow velocity and direction of stream flow;
• thermo-anemometer probes (Constant Temperature Anemometry, CTA) mounted on a sliding measuring ring;
• high accuracy temperature sensors (can be mounted on a sliding measuring ring);
• static pressure ports and static pressure scanners allowing measurement at 40 points;
• piezoelectric pressure sensors for detecting the onset of rotor blade stall;
• ambient conditions monitoring station (humidity, ambient temperature);
• a fully automated traversing ring that allows 360-degree rotation and radial immersion of 4 different probes in the flow. The ring can be mounted on any flow station (at the inlet, in front of the disturbance screen, in front of the rotor, between the rotor and stator and behind the stator);
• measuring apparatus for measuring tip clearance and blade deflection (Blade Tip Timing/Blade Tip Clearance, BTT/BTC) in real time. measuring apparatus based on laser probes (light probe type).