ONERA performed in its large sonic wind tunnel S1MA, the first series of tests of an open rotor (UHB propfan)

During the first half of 2011, ONERA performed in its large sonic wind tunnel S1MA in Modane France, the first series of tests of an open rotor (UHB propfan).  The “HERA” test rig was built in association with SNECMA.  The rig is equipped with a pneumatic drive system for two counter-rotating propellers, and two ONERA rotating 6-component balances, one for each rotor.  Different propeller pairs are fitted to the rig for performance and noise assessments.
These tests have allowed initial aerodynamic and acoustic measurements of this type of propulsion. A non-intrusive method for measuring blade deformations (optical method) was also evaluated during this test campaign.
The first results have demonstrated that the test rig and the associated instrumentation are fully suitable for the test objectives. ONERA is in the design phase of other rigs to assess the performance of an installed open rotor on a fuselage.