An orbital platform rotary balance system for the IAR water tunnel

A rotary balance apparatus based on the orbital platform concept has been developed for use in the IAR Water Tunnel. The new testing capability was introduced to generate a supplementary rotary data base for the F/A-18 aircraft required in a simulator fidelity enhancement study. The F/A-18 model was tested in steady coning motion at angles of attack from 0 deg to 90 deg and non-dimensional rotation rates from 0 to /spl plusmn/0.3. The paper focuses on the new rotary balance testing methodology. Samples of the results are presented to illustrate the uniqueness of the new rotary data base. Agreement with existing wind tunnel data is generally good. Support interference effects in the conventional rotary apparatus were found to be small for this aircraft configuration.