Cal Poly's AMELIA 10 Foot Span Hybrid Wing-Body Low Noise CESTOL Aircraft Wing Tunnel Test and Experimental Results Overview

Abstract

A collaboration between California Polytechnic Corporation with GeorgiaTech Research Institute (GTRI) and DHC Engineering worked on a NASA NRA to develop predictive capabilities for the design and performance of Cruise Efficient, Short Take-Off and Landing (CESTOL) subsonic aircraft. The work presented in this paper gives details of a large scale wind tunnel effort to validate predictive capabilities for this NRA for aerodynamic and acoustic performance during takeoff and landing. The model, Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA), was designed as a 100 passenger, N+2 generation, regional, cruise efficient short takeoff and land (CESTOL) airliner with hybrid blended wing-body with circulation control. AMELIA is a 1/11 scale with a corresponding 10 ft wing span. The National Full-Scale Aerodynamic Complex (NFAC) 40 ft by 80 ft wind tunnel was chosen to perform the large-scale wind tunnel test. The NFAC was chosen because both aerodynamic and acoustic measurements will be obtained simultaneously, the tunnel is large enough that the 2 downwash created by the powered lift did not impinge on the tunnel walls, and the schedule and cost fit into Cal Poly's time frame and budget. Several experimental measurement techniques were used to obtain the necessary data to validate predictive codes being developed as apart of this effort: along with the traditional forces and moments measurements, stationary microphones were used to obtain far-field acoustic measurements including a 48 element phased array, the Fringe-Image Skin Friction (FISF) technique was used to measure the global skin friction on the wing, surface mounted steady and unsteady pressure transducers were used to obtain local pressure distributions over the model, and oil and smoke flow visualization techniques were employed to understand the effects of the powered lift system in AMELIA. The paper gives a brief summary of AMELIA's performance for variable tunnel speed, momentum mass flow, engine simulator height, and angle of attack.

Transonic Drag Reduction Through Trailing-Edge Blowing on the FAST-MAC Circulation Control Model

“…Axial Force, lbf M any of the advanced future aircraft being designed today utilize advanced propulsion and active flow control systems that closely integrate the engine and airframe. [1][2][3][4][5][6] Cruise efficiency, community noise, and runway independence can no longer be optimized independently because of the close coupling of the engine, airframe, and wing. Circulation control techniques have experienced a resurgence recently, with many research efforts focusing on developing databases for CFD validation, [7][8][9][10][11][12][13] as unreliable predictions have been a barrier to applying the techniques to aircraft.…”

“…The NTF 20, 21 is one of a limited number of wind tunnel facilities that can achieve flight Reynolds numbers and Mach numbers for subsonic transport type aircraft for both cruise and high-lift operations. 22 The tunnel is a fan-driven, closed-circuit, continuous-flow, pressurized wind tunnel capable of operating either in dry air at warm temperatures up to 120 • F or in nitrogen gas from warm to cryogenic temperatures down to -270 • F. The wind tunnel is capable of an absolute pressure range from 1 to 9 atmospheres, a Mach number range from 0.1 to 1.2, and a maximum unit Reynolds number of 146x10 6 per foot. Figure 3 shows the major components of the NTF tunnel circuit, including the location of the sidewall model support system (SMSS) used for semispan model testing and the location of the high pressure air (HPA) delivery station needed for propulsion simulation and flow control experiments.…”

“…The FAST-MAC model shown in Figure 8 has a modern super-critical wing and was designed to become an NTF standard for evaluating performance characteristics of integrated active flow control and propulsion systems. The outer mold line (OML) of the model was designed for a cruise Mach number of 0.85 and a lift coefficient of 0.50, at a Reynolds number based on mean aerodynamic chord of 30x10 6 . A tangential blowing slot is located at the 85% chord location on the upper surface, and is directed over a 15% chord simple hinged flap for both the cruise and high-lift configurations.…”

Jet-Surface Interaction Noise from High Aspect Ratio Nozzles: Test Summary

“…The push to high bypass ratio engines in traditional engine-under-wing applications, for example, has placed the exhaust flow close to the underside of the wing; any noise produced by this flow-surface interaction can be directly radiated to people on the ground. In contrast, some concept aircraft have moved the engine pods over the wing 1 or fuselage 2 so that the surfaces might shield ground observers from a portion of the engine noise produced. While some of these designs maintain a traditional engine-pylon architecture, other more futuristic concepts change the entire propulsion system in an effort to reduce noise.…”

Implementation of a correction factor for the Pohlhausen laminar boundary layer applied on the CEVA curved wall jet model

“…Applications of curved wall jets -subject to the Coandă effect -have long been implemented in the aeronautical industry in obtaining higher lift -such as the USB Refs [1][2][3] Fig.1 a. or entrainment Refs [4][5][6][7] Fig.1 b. wings, or replacing the wing altogether Refs [8,9] Fig.1 c; other applications refer to replacing stability control devices such as the helicopter tail rotor with a Coandă-effect curved wall jet on the rotorcraft tail boom Ref [10][11] Fig. 1 Although analytical models were developed for estimating the flow fields over curved surfaces Ref [12], or dedicated turbulence models which compensate for wall curvature Ref [13] or [14], the semi-empirical models such as the ones described by Lewinsky and Yeh [15] or Seed [16] still offer the advantage of being experimentally validated in their design range.…”