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Tram Summary | Tram Organization Chart

TRAM Project Details

Tiltrotor Aeroacoustic Model

The Tiltrotor Aeroacoustic Model will be used as a test bed for testing moderate-scale tiltrotor models in two different test configurations in different research facilities: (1) Isolated Rotor testing at the Duits-Netherlands Windkannal (DNW) in The Netherlands; and (2) Isolated Rotor and Full-Span testing at the National Full-Scale Aerodynamic Complex (NFAC) at Ames Research Center.

DNW Photo

Duits - Nederlandse Windtunnel

A checkout test of the Tiltrotor Aeroacoustic Model (TRAM) isolated rotor test stand is currently being conducted in the National Full-Scale Aerodynamics Complex N246 Model Preparation building. The checkout testing includes the acquisition of hover data -- including rotor airloads data -- for a 1/4-scale set of proprotor blades using the NFAC NPRIME data acquisition system. Key test stand capabilities being checked out include a Nationaal Lucht-en Ruimtevaartlaboratorium (NLR) developed rotating amplifier system (RAS) and the MFEDS real-time safety of flight monitoring system. A considerable amount of infrastructure build-up -- including armor plate shielding and control room installation -- was required in N246 to enable TRAM functional testing.

TRAM Closeup Photo

The full-span version of the TRAM test stand is also being concurrently developed. Fabrication of full-span model development is underway and the bulk of the hardware was delivered in June 1997. A new generation rotor control console for the isolated rotor test and the full-span model is also in development; delivery of the console is scheduled for the end of March 1997.

The 1/4-scale TRAM rotors and airframe are based on the V-22 Osprey tiltrotor aircraft. The TRAM test stand will also be an advanced technology demonstrator platform for the Short Haul Civil Tiltrotor (SH(CT)) program, a sub-element of the Advanced Subsonic Transport (AST) initiative. Both Boeing and Sikorsky Aircraft have been contracted by the NASA SH(CT) program to develop interface hardware to test a new generation of small-scale, advanced proprotors on the TRAM test stand. The Boeing and Sikorsky proprotors are planned to be tested on the full-span TRAM test stand in the NFAC 40- by 80-Foot Wind Tunnel. The full-span TRAM proprotor testing is currently planned for FY 99-01. Larry A. Young, (650)604-4022.

A Brief Recap - TRAM Objectives

  • Acquire 1/4-scale V-22 isolated rotor acoustic and airload data to enable the development of next-generation, quieter proprotors
  • Acquire dual-rotor, full-span airframe proprotor data to establish interactional aeroacoustic and aerodynamic performance effects (validation with TRAC & other rotor aeroacoustic prediction codes)
  • Demonstrator Test Platform for Advanced Proprotors for the SH(CT) Program
  • TRAM Angle PhotoA Brief Recap - Description/Capabilities of TRAM (Isolated Rotor)

  • 1/4-scale V-22 rotor set (strain-gaged and pressure-instrumented blades)
  • Gimbaled hub with constant velocity joint (spherical bearing and elastomeric torque links)
  • Six-component rotor balance and instrumented torque coupling
  • 300-ring slip ring and rotating amplifier system
  • Drive train designed for nominal 300 HP and 18,000 RPM motor; two transmissions and 11.3:1 gear reduction
  • Nacelle incidence angle is ground adjustable
  • Test stand is WT sting-mounted
  • A Brief Recap - Description/Capabilities of TRAM (Full-Span)

    Full-Span TRAM Photo
  • 1/4-Scale Representation of the V-22 airframe
  • Two Rotor Balance & a Model/Fuselage Balance
  • Drive Train Designed to Deliver 300 HP to Each Rotor
  • Model Capable of Being Tested to 300 Knots (Maximum Speed Capability of NFAC)
  • Flaperons (total of 4) and Elevator are Remote- Controlled; Rudders are Ground-Adjustable
  • Nacelle Tilt Angle is Ground-Adjustable
  • Model Support is Designed for Minimum Interference & Maximum Load Capacity
  • DNW/Isolated Rotor Status - Motors & Motor Drive/Controller

  • Primary motor option for TRAM DNW test is use of existing motor assets & a Pillar MG-set: a 'baseline' GE motor or a water-cooled-shaft motor
  • Existing motor assets are likely be able to provide 150HP; this will be confirmed in next couple of weeks with high-speed dyno testing conducted here at AMES
  • Irrespective of motor power capability, Pillar MG-set will limit power to approximately 150HP
  • Successes achieved with new motor development (Kaman Electromagnetics) but some redesign is required in motors; motors will not be available in time for DNW
  • DNW/Isolated Rotor Status - Rotor Control Console & Actuators

  • TRAM Rotor control console delivered to AMES
  • Console is capable of operating either an isolated rotor or dual rotors; dual rotor operation can either be slaved together or independently controlled
  • Both RH & LH rotor actuator sets delivered to AMES; actuators and simplified control system used in console development
  • Console/actuator acceptance testing of vendors has been reproduced at AMES; more extensive functional testing is in progress
  • Line drivers and 300ft control harnesses need to be fabricated
  • TRAM Represents Next Wave Rotorcraft Test Technology

  • New rotor control console technology
  • New real-time monitoring approach (MFEDS)
  • Digital/GUI approach for model health monitoring system
  • Closed-Loop Fixed-wing Control Console
  • Digital/GUI approach for Motor Controller
  • New generation for programmable filter/signal conditioning equipment
  • Rotating Amplifier System/High-Capacity Slip-Ring Technology (RAS)
  • High-Speed, All-Dynamic Data Channels for NPRIME Rotor Databases
  • Near-real-time acoustic data reduction and synchronization with other data channels
  • Current/Future Spin-Off Successes

  • MFEDS: already employed on non-TRAM rotorcraft programs - XV-15/RTA Acoustics Test in NFAC 80-by120 Foot WT
  • RAS: U.S. Army has developed a derivative version of RAS for their own rotorcraft research programs
  • TRAM rotor control console: Large Rotor Test Apparatus (LRTA) will employ TRAM rotor control console technology for a new console to support UH-60/Full-scale V-22 testing
  • Non-Freon Based Slipring Technology: Pratt Witney, GE, U.S. Army, and NASA have exchanged operational experience information in this area
  • Industry Technology Transfer

  • All four Short Haul Civil Tiltrotor [SH(CT)] Industry partners have access to technology developed as a part of TRAM program
  • NASA Langley and U.S. Army (AFDD at Ames) have access as well.
  • Point of Contact:

    Larry Young
    NASA Ames Research Center
    Moffett Field CA 94035-1000

    U.S. Rotorcraft Company links

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