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MV-22B Short Takeoff and Minimum Run-On Landing tests Aboard Nimitz-Class Ships

JOURNAL OF AIRCRAFT 2022年第2期59卷 307-316页

作者： Gibson, James R. Mitchell, Virginia Embry Riddle Aeronaut Univ Decis Sci Daytona Beach FL 32114 USA Lockheed Martin Marietta GA 30060 USA

Tiltrotor aircraft ship suitability and envelope expansion testing aboard a U.S. Navy aircraft carrier is discussed. The purpose was to validate and expand day/night vertical launch and recovery wind envelopes, and the development of short takeoff and minimum run-on landing wind envelopes. The preparation phase incorporated a six-degree-of-freedom motion flight simulator to evaluate flight dynamics prior to on-shore testing using V-22 developmental and production aircraft. The short takeoff and minimum run-on landing testing totaled 12.3 flight hours with 33 takeoffs and 32 landings. The gross weights ranged from 51,000 to 57,000 lb with +/- 15deg of relative wind from 0 to 45 kt. The test pilots provided assessments of handling and flying qualities throughout the maneuvers using the deck interface pilot effort scale. Predictability tests were required to determine the pilot's ability to land within the defined touchdown zone and speeds for safely stopping within the braking zone. The results show the integrated nature of shipboard flight testing and the process of combining pilot workload ratings, control strategies, and aerodynamic analyses to field a needed capability.

关键词： flight test programme Crew Member Queen Elizabeth Class Aircraft Carrier Handling Qualities Tiltrotor Aircraft Six Degree of Freedom flight Simulators flight Dynamics Integrated flight Control System Helicopter Rotor

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HOVER ACOUSTIC CHARACTERISTICS OF THE XV-15 WITH ADVANCED TECHNOLOGY BLADES

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JOURNAL OF AIRCRAFT 1994年第4期31卷 737-744页

作者： CONNER, DA WELLMAN, JB NASA Langley Research Center Hampton Virginia 23681 NASA Ames Research Center Moffett Field California 94035

An experiment has been performed to investigate the far-field hover acoustic characteristics of the XV-15 aircraft with advanced technology blades (ATB). An extensive, high-quality, far-field acoustics data base was obtained for a rotor tip speed range of 645-771 ft/s. A 12-microphone, 500-ft radius semicircular array combined with two aircraft headings provided acoustic data over the full 360-deg azimuth about the aircraft with a resolution of 15 deg. Altitude variations provided data from near in-plane to 45 deg below the rotor tip path plane. Acoustic directivity characteristics in the lower hemisphere are explored through pressure time histories, narrow-band spectra, and contour plots. Directivity patterns were found to vary greatly with azimuth angle, especially in the forward quadrants. Sharp positive pressure pulses typical of blade-vortex interactions were found to propagate aft of the aircraft and were most intense at 45 deg below the rotor plane. Modest overall sound pressure levels were measured near in-plane indicating that thickness noise is not a major problem for this aircraft when operating in the hover mode with ATB. Rotor tip speed reductions reduced the average overall sound pressure level [dB (0.0002 dyne/cm2)] by nearly 8 dB in-plane, and by almost 5 dB at 12.6 deg below the rotor plane.

关键词： Overall Sound Pressure Level Band Spectra Blade Vortex Interaction Acoustic Measurement Rotor Blades Tiltrotor Aircraft flight test programme Rotor Systems Landing Gear GOES Satellites

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flight-test EVALUATION OF ENGINE POWER EFFECTS ON LIFT AND DRAG

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JOURNAL OF AIRCRAFT 1985年第5期22卷 409-414页

作者： YECHOUT, TR SCHWEIKHARD, WG BRAMAN, KB United States Air Force Academy CO Colorado Springs United States University of Kansas Lawrence KS United States Lt. Col. USAF United States

A flight-test technique has been developed under NASA Dryden sponsorship to define the aerodynamic effect of thrust level on aircraft lift and drag characteristics. Conventional stabilized “speed power” tests require the thrust to be adjusted for each test condition and, as a result, the effect of thrust on aerodynamic characteristics cannot be easily identified. The technique utilizes quasi-steady-state maneuvers at selected power settings throughout the Mach range of the aircraft to define lift and drag coefficient variation as a function of angle of attack, Mach number, and power setting. A 20-h verification flight-test program was accomplished using a Learjet Model 35 aircraft. Significant power effects were identified which should be anticipated on any aircraft with jet engines mounted on the aft fuselage above the inboard wing section. © 1985 American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： flight test programme Lift Coefficient Aerodynamic Characteristics Fuselages Quasi Steady States Jet Engines Skin Friction Coefficient Wing Root Aircraft Performance Dynamic Pressure

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flight test OF THE F100-PW-220 ENGINE IN THE F-16

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JOURNAL OF PROPULSION AND POWER 1989年第5期5卷 620-625页

作者： CHILDRE, MT MCCOY, KD General Dynamics Corporation Fort Worth Texas

The F-100-PW-220 engine has provided excellent improvement to the overall operability of the F-16 weapons system. A thorough 106-flight, two-phase, test program demonstrated the overall capability and compatibility of the F100-PW-220 engine. Results demonstrated that the F100-PW-220 produces comparable thrust and significantly improved response over its F100-PW-200 predecessor. Improved augmentor operability and start characteristics have reduced pilot work load greater and permitted greater attention to the mission at hand. A minimum number of problems were encountered, addressed, and/or corrected in an air of cooperation.

关键词： flight test programme Digital Electronic Engine Control Thrust Specific Fuel Consumption Airspeed Aircraft Maneuvers Pilot Angle of Attack flight Envelope Airframes Fault Detection

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RAMJET DEVELOPMENT testING - WHICH WAY IS RIGHT

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JOURNAL OF PROPULSION AND POWER 1989年第5期5卷 565-576页

作者： WEBSTER, FF Martin Marietta Missile Systems Orlando Florida

Ramjet propulsion systems evolved into a modern era starting in the mid 1960's with the advent of the integral rocket ramjet concept. At least 10 different liquid-fueled ramjet propulsion arrangements for potential missile applications have been evaluated in ground testing during this period, with three concepts having proceeded through flight testing. This paper identifies some of the problems and pitfalls discovered during those development programs. An overview is given of the various types of ramjet propulsion systems that have been evaluated in test programs. The various ramjet testing techniques are summarized along with major difficulties that have been encountered. Recommendations are made for essential hardware arrangements and test procedures needed to evaluate performance characteristics properly. A comparison is made of the different categories of propulsion arrangements which shows how preferred testing programs may vary among the different types of configurations.

关键词： Ramjet Engines flight test programme Propulsion System Rockets Liquid Fuels Combustors Aerodynamic Characteristics Angle of Attack Propellant Wind Tunnel Models

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Numerical Analysis of Aerodynamic Characteristics of Iced Rotor in Forward flight

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AIAA JOURNAL 2019年第4期57卷 1523-1537页

作者： Chen, Xi Zhao, Qijun Barakos, George Nanjing Univ Aeronaut & Astronaut Sch Aeronaut & Astronaut Nanjing 210016 Jiangsu Peoples R China Univ Glasgow CFD Lab Sch Engn Glasgow G12 8QQ Lanark Scotland

Based on a three-dimensional rotor icing model and the CLORNS code, aerodynamic characteristics of iced rotors in forward flight are calculated and analyzed. At first, ice accretion on the UH-1H rotor in hover and ice accretion on the spinning rotor blade rotor in forward flight are calculated. The results are used to validate the employed numerical simulation method through comparisons with experimental data. Then, the degradation of the aerodynamic characteristics of the iced SRB rotor is analyzed, and the variation of the pressure coefficients on the rotor blades is discussed in detail. Finally, parameters such as the icing time, the temperature, and the icing position are quantified, and conclusions are obtained. The influence of the ice accretion on the sectional aerodynamic characteristics increases along the spanwise direction, and deicing near the 0.7R blade section should be preferred at the beginning of the ice accretion. Finally, it is concluded that ice will not be removed in time if the deicer is activated based solely on the variation of the rotor aerodynamics.

关键词： Aerodynamic Characteristics Reynolds Averaged Navier Stokes Numerical Simulation Rotor Blades Numerical Analysis Lift Coefficient Helicopter Rotor Low Turbulence Pressure Tunnel flight test programme NASA Langley Research Center

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Simulation and analysis of V-22 tiltrotor aircraft forward-flight flowfield

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JOURNAL OF AIRCRAFT 1996年第2期33卷 369-376页

作者： Tai, TC U.S. Navy Naval Surface Warfare Center Bethesda MD

The flowfield about a wing-fuselage-nacelle configuration of the V-22 tiltrotor aircraft at a freestream Mach number of 0.345 and angles of attack ranging from 7 to 16 deg is simulated by using a multizone, thin-layer Navier-Stokes method The flow conditions yield a Reynolds number of 18.2 x 10(6) based on the wing chord for flight at an altitude of 10,000 ft. Major flow features including the three-dimensional flow separation from viscous-vortex interactions observed experimentally are captured by the simulation. The massive separation from the wing and the fore fuselage-sponson region for hows at high angles of attack creates free vortices that pass by the rear fuselage region, including the tail section of the aircraft.

关键词： Tiltrotor Aircraft Fuselage Sponson Aerodynamic Performance Vortex Breakdown Aerodynamic Simulation Aerodynamic Flows Flow Separation flight test programme Wing Root Spalart Allmaras Turbulence Model

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CTOL SKI JUMP - ANALYSIS, SIMULATION, AND flight test

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JOURNAL OF AIRCRAFT 1986年第5期23卷 382-389页

作者： CLARK, JW WALTERS, MM Naval Air Development Center Warminster Pennsylvania

In the past several years, the ski-jump (ramp-assisted) lauuch concept has received considerable attention within the U. S. Navy. The specific goal was set (and achieved) to demonstrate through flight test the feasibility of, and quantify performance gains from, ski-jump launch of the T-2C, F-14A, and F/A-18A aircraft using a 100-ft ramp with variable end angles of 6 and 9 degs. The analysis, piloted simulation, performance predicitions, and flight safety considerations leading to flight test, as well as a comparison of analytical predictions with flight test results for the three aircraft, are discussed. The developed analytical capability, although somewhat conservative, proved to be highly effective in preparation for, and support of, the flight test and in successfully predicting the 40-60% reduction in takeoff distance demonstration in flight test.

关键词： flight test programme Conventional Takeoff and Landing Rate of Climb Aircraft Configurations Aeroplane Pilot Three Degrees of Freedom Pilot Modeling flight Simulation Angle of Attack

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Mach Number Effect of Compressible Flow Around a Circular Cylinder

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AIAA JOURNAL 2016年第6期54卷 2004-2009页

作者： Xia, Zhenhua Xiao, Zuoli Shi, Yipeng Chen, Shiyi Peking Univ State Key Lab Turbulence & Complex Syst Beijing 100871 Peoples R China South Univ Sci & Technol China Shenzhen 518055 Peoples R China

Compressible gas flow past a circular cylinder is numerically studied through CLES approach. The emphasis is put on the influences of freestream (inflow) Mach number on the aerodynamic performances of subsonic and transonic circular cylinders and the flow patterns around the cylinders at subcritical and supercritical Reynolds number regions. Some statistical quantities are calculated and analyzed with respect to freestream (inflow) Mach number. It is found that drag coefficient at different Reynolds number shows a similar trend with small deviations as freestream (inflow) Mach number increases, although these two Reynolds number are of two orders of magnitude difference. However, mean separation angle shows apparent differences. Therefore, it is inferred that the effect of freestream (inflow) Mach number on the drag force prevails over that of Reynolds number in high subsonic and transonic flows. In low Reynolds number flows, the response of mean separation angle to the changes freestream (inflow) Mach number is similar to that of drag coefficient. It is also found that there exists a subcritical Mach number, across which the development of flow fluctuations and the resulting flow patterns show distinct characteristics. It is suggested that subcritical Mach number be between 0.7 and 0.75 for low Reynolds number flows, and fall between 0.65 and 0.7 for high Reynolds number flows.

关键词： Aerodynamic Properties Incompressible Flow Direct Numerical Simulation Adverse Pressure Gradient Boundary Layer Separation Vortex Shedding Phenomena flight test programme Aerodynamic Performance Compressibility Skin Friction Coefficient

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Fault Analysis and Solution of an Airplane Nose Landing Gear's Emergency Lowering

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JOURNAL OF AIRCRAFT 2016年第4期53卷 1022-1032页

作者： Yin Yin Nie Hong Wei Xiaohui Chen Heng Zhang Ming Nanjing Univ Aeronaut & Astronaut Key Lab Fundamental Sci Natl Def Adv Design Techn Nanjing 210016 Jiangsu Peoples R China

In this paper, the fault analysis of an aircraft nose landing gear's emergency lowering was conducted with a cosimulation method. The simulation was aimed at studying the dynamic response characteristics of landing-gear retraction/extension. Moreover, the equations of the mechanical and hydraulic system were derived and analyzed so as to acquire the boundary condition under which the landing-gear emergency lowering could fail. Based on the simulation platform computer aided engineering, a cosimulation model ( including a dynamic system and a hydraulic system) was developed, after which, by comparing the simulation results with the data of the ground test and flight test, the model was further verified. Additionally, the nose landing gear could succeed in emergency lowering with the premise that the critical dampings of different flight cases and temperatures were obtained. After that, a feasible scheme of emergency lowering was put forward. The results showed that, at the end of the landing-gear lowering process, the favorable moment saltation produced by the spring force could lag behind the unfavorable moment saltation of the aerodynamic force of the front and back cabin doors, thus resulting in the fault of emergency lowering and locking. Furthermore, when the method of decreasing the damping force was adopted, the landing gear would succeed in emergency lowering only by adjusting the force down to the critical value. However, due to the reduced damping force, the lowering process could be made so fast that there was a great impact load on the landing gear at the end of the trip. The solution laid in using the original damping value in normal extension and the reduced damping value in emergency lowering by a hydraulic selector valve.

关键词： Nose Landing Gear Aeroplane Aerodynamic Center Hydraulic Actuators Gear Retraction flight test programme Computer Aided Engineering Dynamic Response Kinematic Viscosity Federal Aviation Regulation

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