STATUS REPORT ON ADVANCED DEVELOPMENT PROGRAM UTILIZING CIRCULATION CONTROL ROTOR TECHNOLOGY.

The current status of circulation control aerodynamics research and of two full-scale flight demonstrator aircraft development programs, employing circulation control rotors, is presented. The development of circulation control technology has taken an orderly progression from two-dimensional airfoil experiments and analytical studies through three-dimensional subscale rotor experiments and correlation to full-scale rotor development and flight tests. The first program, the Circulation Control Rotor (CCR), includes the installation of a conventional speed circulation control rotor on an existing H-2D airframe. The second program consists of the development of a new VTOL aircraft, the stopped rotor X-Wing. Both of these programs are scheduled to be tested in the NASA Ames 12 multiplied by 24 m (40 multiplied by 80 ft) wind tunnel during late 1978. In-house laboratory research programs leading to the translation of CCR and X-Wing technologies into industry are described. Current status of the CCR design, fabrication, and initial whirl stand validation efforts, in preparation for the July 1978 tests in the Ames tunnel, are described. Also described are the results of a preliminary design study and hardware fabrication program for the X-Wing.