A 1:3 scaled model fan being representative for a High Bypass-Ratio aero engine was designed, tested and aerodynamically investigated at the German Aerospace Center (DLR) to achieve an environmental-friendly engine with high efficiency and low noise emissions. In order to assess it and to get a deeper understanding of design relevant flow phenomena, simulations and measurements with specific instrumentations were carried out. The casing has been instrumented with ten piezoelectric static pressure probes used to measure the unsteady static pressure above the rotor. Hot-wire probes are mounted on traverse between the rotor and the stator and they allow to measure the radial profile of the flow velocity. Both experimental data required a phase-locked, ensemble-averaging procedure and were analyzed in the time domain as well as in the frequency domain. Static pressure contour plot and the three components contour plot of the velocity give details of the flows structures. Steady numerical simulations of the UHBR geometry are achieved with the DLR in-house solver TRACE for different operating conditions. The results include the global performance of the compressor and the thesis focuses on detailed comparisons between simulation and measurement for the instrumentation available. The results confirm that the overall flow structures are properly represented in the numerical simulations. The same phenomena and their evolution can be observed.
Figure 1: DLR-UHBR Fan test rig at the Institute of Propulsion Technology’s compressor facility M2VP (left) and measured and calculated stage performance characteristic (right)
Figure 2: Fast response pressure transducers in the casing above the fan rotor (left), comparison of measured and simulated static pressure contours yielding all relevant flow structures such as tip clearance vortex as well as expansion and diffusion regions in the blade-to-blade passage (right).
Figure 3: Results from hot-wire measurements in the axial gap between the fan rotor and the OGV. Shown is the rotor wake induced velocity deficit at different radial heights in comparison with the CFD data from TRACE calculations.