Aircraft Research Association

ARA

Model Preparation Facilities

Introduction

ARA has all the facilities required to prepare a model for test from balance calibration to model assembly.

Balance Calibration

Balcal

All ARA balances are calibrated in-house in the Balance Calibration Laboratory – this service is also available for customer supplied items.

The features of this facility include:

  • Standard equipment used to perform dead weight loadings in the calibration frame, which incorporates pitch and roll levelling mechanisms
  • Non-standard balance set ups supplied with the necessary specialised loading adaptors.
  • A balance calibration matrix produced from a full set of interactive calibrating load cycles, including first and second order interaction terms
  • Checks against hysteresis in balance/sting joints
  • Deflection measurements of support systems
  • Checks to ensure interference free operation of live elements
     
    For a typical civil aircraft drag model balance, the achieved resolution of ±0.11N (±0.025lbf) in axial force components and ±0.60N (±0.135lbf) in normal force components in static calibration is equivalent to ∆CA = 0.000014 and ∆CN = 0.000075 for a typical qS of 8000N (1800lbf)

Secure Model Bays

Model Bay

There are five model preparation bays (four of which are secure) which are connected to the working section of the Transonic Wind Tunnel (TWT) by a system of tracks and turntables.

Each model is fully assembled in a secure model bay on a dedicated cart which supports the model when installed in the test section of the TWT. Once the model preparation and instrumentation checks have been completed, the model cart is wheeled into the TWT test section.

After the test, any post-test checks and model disassembly are carried out in the model bays where the model is prepared for storage or dispatch.

Depending on the security level required by the customer, models can be covered with blackout covers to disguise the model during transit between the model bay and TWT test section.

Pressure Sensitive Paint Spray Booth

A spray booth for the preparation of PSP has recently been installed; please see the Innovation and Technology section for further details.

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