Download or read book Effect of Actuated Forebody Strakes on the Forebody Aerodynamics of the NASA F 18 Harv written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive pressure measurements and off-surface flow visualization were obtained on the forebody and strakes of the NASA F-18 High Alpha Research Vehicle (HARV) equipped with actuated forebody strakes. Forebody yawing moments were obtained by integrating the circumferential pressures on the forebody and strakes. Results show that large yawing moments can be generated with forebody strakes. At angles of attack greater than 40 deg., deflecting one strake at a time resulted in a forebody yawing moment control reversal for small strake deflection angles. At alpha = 40 deg. and 50 deg., deflecting the strakes differentially about a 20 deg. symmetric strake deployment eliminated the control reversal and produced a near linear variation of forebody yawing moment with differential strake deflection. At alpha = 50 deg. and for 0 deg. and 20 deg. symmetric strake deployments, a larger forebody yawing moment was generated by the forward fuselage (between the radome and the apex of the leading-edge extensions), than on the radome where the actuated forebody strakes were located. Cutouts on the flight vehicle strakes that were not on the wind tunnel models are believed to be responsible for deficits in the suction peaks on the flight radome pressure distributions and differences in the forebody yawing moments. Fisher, David F. and Murri, Daniel G. and Lanser, Wendy R. Unspecified Center RTOP 505-68-30...
Download or read book Effect of Actuated Forebody Strakes on the Forebody Aerodynamics of the NASA F 18 HARV written by David F. Fisher and published by . This book was released on 1996 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Actuated Forebody Strakes on the Forebody Aerodynamics of the NASA F 18 HARV written by David F. Fisher and published by . This book was released on 1996 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forebody Aerodynamics of the F 18 High Alpha Research Vehicle with Actuated Strakes written by and published by . This book was released on 2003 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive pressure measurements and off-surface flow visualization were obtained on the forebody and strakes of the NASA F-18 High Alpha Research Vehicle (HARV) equipped with actuated forebody strakes. Forebody yawing moments were obtained by integrating the circumferential pressures on the forebody and strakes. Results show that large yawing moments can be generated with forebody strakes. At a 500-angle-of attack, deflecting one strake at a time resulted in a forebody yawing moment control reversal for small strake deflection angles. However, deflecting the strakes differentially about a 200 symmetric strake deployment eliminated the control reversal and produced a near linear variation of forebody yawing moment with differential strake deflection. At an angle of attack of 500 and for O% and 200 symmetric strake deployments, a larger forebody yawing moment was generated by the forward fuselage (between the radome and the apex of the leading-edge extensions) than on the radome where the actuated forebody strakes were located. Cutouts on the flight vehicle strakes that were not on the wind tunnel models are believed to be responsible for deficits in the suction peaks on the flight radome pressure distributions and differences in the forebody yawing moments.
Download or read book Forebody Flow Visualization on the F 18 HARV with Actuated Forebody Strakes written by David F. Fisher and published by . This book was released on 1998 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Off-surface smoke flow visualization and extensive pressure measurements were obtained on the forebody of the NASA F-18 High Alpha Research Vehicle equipped with actuated forebody strakes. Test points at [alpha]=50 deg. were examined in which only one strake was deflected or in which both strakes were deflected differentially. The forebody pressures were integrated to obtain forebody yawing moments. Results showed that small single strake deflections can cause an undesirable yawing moment reversal. At [alpha]=50 deg., this reversal was corrected by deploying both strakes at 20 deg. initially, then differentially from 20 deg. to create a yawing moment. The off-surface flow visualization showed that in the case of the small single strake deflection, the resulting forebody/strake vortex remained close to the surface and caused accelerated flow and increased suction pressures on the deflected side. When both strakes were deflected differentially, two forebody/strake vortices were present. The forebody/strake vortex from the larger deflection would lift from the surface while the other would remain close to the surface. The nearer forebody/strake vortex would cause greater flow acceleration, higher suction pressures and a yawing moment on that side ot the forebody. Flow visualization provided clear description of the strake vortices fluid mechanics.
Download or read book Using the HARV Simulation Aerodynamic Model to Determine Forebody Strake Aerodynamic Coefficients from Flight Data written by Michael D. Messina and published by . This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The method described in this report is intended to present an overview of a process developed to extract the forebody aerodynamic increments from flight tests. The process to determine the aerodynamic increments (rolling pitching, and yawing moments, Cl, Cm, Cn, respectively) for the forebody strake controllers added to the F/A - 18 High Alpha Research Vehicle (HARV) aircraft was developed to validate the forebody strake aerodynamic model used in simulation.
Download or read book NASA Aerodynamics Program Annual Report 1990 written by Louis J. Williams and published by . This book was released on 1991 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Summary of the Forebody High angle of attack Aerodynamics Research on the F 18 and the X 29A Aircraft written by and published by . This book was released on 1992 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EFFECT OF ACTUATED FOREBODY STRAKES ON THE FOREBODY NASA TM 4774 MAR 24 1997 written by United States. National Aeronautics and Space Administration and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1991 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Tunnel Investigations of Forebody Strakes for Yaw Control on F A 18 Model at Subsonic and Transonic Speeds written by Gary E. Erickson and published by . This book was released on 1993 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The F A 18 High Angle of Attack Ground to Flight Correlation Lessons Learned written by and published by . This book was released on 1997 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1999 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Method for Integrating Thrust Vectoring and Actuated Forebody Strakes with Conventional Aerodynamic Controls on a High Performance Fighter Airplane written by Frederick J. Lallman and published by . This book was released on 1998 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Forebody Strakes and Mach Number on Overall Aerodynamic Characteristics of Configuration with 550 Cropped Delta Wing written by and published by . This book was released on 1992 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book F A 18 Forebody Vortex Control Volume 1 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wind tunnel test was conducted on a six percent model of the F/A-18 at the NASA Ames 7 X 10-Foot Low Speed Wind Tunnel. The primary objective of the test was to evaluate several forebody vortex control configurations at high angles of attack in order to determine the most effective method of obtaining well behaved yawing moments, in preparation for the rotary balance test. Both mechanical and pneumatic systems were tested. Single and dual rotating nose tip strakes and a vertical nose strake were tested at different sizes and deflections. A series of jet blowing configurations were located at various fuselage stations, azimuth angles, and pointing angles ranging from straight aft to 60 deg canted inboard. Slot blowing was investigated for several slot lengths and fuselage stations. The effect of blowing rate was tested for both of these pneumatic systems. The most effective configurations were then further tested with a variation of both sideslip angle and Reynolds number over a range of angles of attack from 0 to 60 deg. It was found that a very robust system can be developed that provides yawing moments at angles of attack up to 60 deg that significantly exceeds that available from 30 deg of rudder deflection (F/A-18 maximum) at 0 deg angle of attack. Kramer, Brian R. and Suarez, Carlos J. and Malcolm, Gerald N. and Ayers, Bert F. Unspecified Center AIRCRAFT CONTROL; ANGLE OF ATTACK; BLOWING; F-18 AIRCRAFT; FOREBODIES; STRAKES; VORTICES; WIND TUNNEL TESTS; BOUNDARY LAYER CONTROL; LATERAL CONTROL; REYNOLDS NUMBER; YAWING MOMENTS...
Download or read book Effects of Forebody Strakes and Mach Number on Overall Aerodynamic Characteristics on Configuration with 55 Degrees Cropped Delta Wing written by Gary E. Erickson and published by . This book was released on 1992 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
