1 gvhobson@nps.edu Garth V. Hobson 15 th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC-15 February 24 - 28, 2014, Honolulu, HI, USA Hobson, G. V., Gannon, A. J., Delagrange, C. T., Clay, C. S. and Jones A. M. Naval Postgraduate School Monterey, CA 93940 USA gvhobson@nps.edu Abstract The operational flexibility of vertical take-off and landing aircraft have given resurgence to the effort for the design of an aircraft which uses a cross- flow fan as its primary means of propulsion. Recent research has been primarily focused on determining the ideal rotor and housing design for use in a cross-flow fan propulsion system, which will generate a trust-to-weight ratio significant enough to allow for vertical take-off. The commercial computational fluid dynamics software, ANSYS CFX, was used to perform computational analyses of various housing designs. A suitable design was identified to construct for experimentation from these analyses. The fan design consisted of a twenty-bladed rotor, whose blade profiles consisted of circular tube sections. The staggering of the blades around the rotor were such that the trailing edge of the first stage was nearly radial and the leading edge of the second stage too was radial. Following the analytical phase, the conceptual housing was fabricated and paired with the rotor to validate the predicted performance. The experimental model was operated at speeds from 4000 to 9000 rpm and successful comparisons were made between the actual and projected thrust calculations. Introduction In 2006, Propulsive Wing patented a new aerodynamic platform that integrates an embedded, distributed cross-flow fan propulsion system within a thick wing [1]. While the current Propulsive Wing models do not have the capability for VTOL, the company has developed an aircraft whose sole means of propulsion is via a CFF. Additionally, as can be seen in Figure 1 and in videos on their website, the Propulsive Wing is capable of near vertical hovering when the plane is oriented at a steep angle of attack, with the CFF operating. The Propulsive Wing demonstration gives much optimism to the future of CFF powered VTOL aircraft. Fig. 1 CFD simulation of the Propulsive Wing at a high angle of attack. From [1] A best design of a simple housing for a Propulsive Wing 16-bladed rotor [2] is shown in figure 2 as a computational mesh. Unsteady computational simulations of the two-dimensional geometry showed promise in their ability to predict the thrust and more importantly the measure power consumption of the 203 mm (8”) span fan. CROSS FLOW FAN DEVELOPMENT FOR PROPULSION OF A VERTICAL TAKE-OFF AND LANDING VEHICLE CROSS FLOW FAN DEVELOPMENT FOR PROPULSION OF A VERTICAL TAKE-OFF AND LANDING VEHICLE