1 May 2003

IAC BUILDS GROUNDBREAKING ENGINE TESTING FACILITY FOR MOD's DARA, UK – setting new standards in turboshaft testing

IAC Aviation has designed and built a turnkey test facility for the UK’s Defence Aviation and Repair Agency (DARA) at Gosport, Hampshire. It sets new standards in turboshaft engine testing. The facility has several groundbreaking design features - such as multi-engine flexibility (the ability to accommodate a wide variety of engines) - and sets new records for speed of engine turnaround.

Complex design
It is generally agreed that turboshaft engine test cells are among the most difficult to design and build successfully. When a single cell must accommodate a variety of different engines, with different exhaust/intake drive and exhaust configurations, the situation becomes even more complicated.

IAC’s extensive experience
In creating the design of the new DARA facility IAC was able to draw on experience gained from several previous projects, notably an RTM322 facility for Rolls-Royce at East Kilbride (UK) and various GEM turboshaft engine facilities for the UK MoD and Norwegian Air Force.

The DARA facility has been designed to handle, initially, the Rolls-Royce Gnome and Turbomeca RTM322 engines. As before, IAC made use of “clean cell” technology to develop the DARA solution and the critical areas of airflow and aerodynamic stability were examined in depth using computational fluid dynamics (CFD).

Turnkey solution

IAC was contracted to handle all aspects of the facility’s design and construction including its acoustic, mechanical, electrical, and civil engineering. The facility consists of the multi-engine test cell, a services enclosure, control room, engine work/preparation shop and facilities block. A steel portal frame building houses the whole complex, inside which are special acoustic enclosures forming the test cell and control room. These high specification IAC ‘Noishield’ panel structures provide essential protection from high test cell noise emissions to workshop personnel and the surrounding environment. A separate fuel enclosure contains the fuel flow metering and fuel conditioning system, with a bunded twin tank bulk fuel system located a safe but convenient distance away. The water system reservoir and cooling tower are located to the rear of the facility.

Principal features

• Multi-engine testing
• Front end and exhaust drive capability
• Bi-directional drive shaft rotation
• Bi-directional airflow
• 'Clean Cell' technology
• IAC's Aquarius Data Acquisition System - allowing 'single-click' engine change
• Fast turnaround using pre-rigged trolleys
• Water conditioning system – water softening and biocide treatment systems, bulk water reservoir and efficient cooling tower to enable round year engine testing
• Integral Engine Workshop/Preparation Area
• Compressor System – for engine start and shop air requirements
• Fire System – protecting the 3 individual Zones of the Test Cell, Fuel Room and Services Enclosure
• Lubrication systems – both for gearbox and torquemeter systems
• Fuel System - including bulk fuel storage, conditioning and fuel flow measurement systems for all engine variants

The Test Cell

The test cell was constructed using high-performance IAC ‘Noishield’ acoustic panels and incorporates appropriate air inlet and exhaust systems. Engines for test are brought to the cell through an acoustically compatible double door from the adjacent engine work/preparation shop. Personnel entry is via a lobby with Noise-Lock acoustic doors at each end which prevent noise from the test cell from entering the control room and the engine preparation area. A further personnel door is located on the opposite side of the test cell for entry into the services enclosure.

Designed to provide full performance testing for the RTM322 and both port and starboard configurations of the Gnome 1400, the engine load is absorbed through a single bi-directional dynamometer, gearbox and torquemeter mounted upon the engine test stand. Engines are brought into the test cell “pre-dressed” on their respective engine trolleys. Trolleys are configured so that they can be quickly mounted on the main test stand and have quick release couplings for all electrical, pneumatic and fluidic connections.

Clean cell approach

The ‘clean cell approach to the design of the test cell means that a minimum amount of equipment is kept within the test cell itself. This ‘clutter-free’ environment improves airflow through the test cell and helps to maintain the quality of the airflow into and, critically, past the engine. An overhead monorail in the test cell allows test stand components to be maneuvered and maintained easily. The control room window is located on the right hand wall of the cell, giving the facility operator a constant, clear view of the engine during testing.

Control room

The acoustic control room has a climatic air-conditioning system to maintain a comfortable working environment for facility operators. Ergonomically-designed control consoles have been provided to allow all facility, plant and control functions to be displayed and adjusted with ease. The control room houses the following main equipment:

• ADAS
• Control Console
• Power Distribution System
• Termination Panel
• Facility Control Panel
• Throttle Control Systems
• Fire Control Panel
• Engine Control Panels
• Vibration Monitoring System

Automatic Data Acquisition

The IAC Aquarius Automatic Data Acquisition System (ADAS) is well proven, fully configurable and ideally suited to the rigorous testing requirements of aero-engine pass-off. The system provides graphics of both steady state and engine life history, all from just one PC. It has been developed as a data acquisition front end, specifically for aero-engine testing, and has comprehensive display, control and logging capabilities. It can be supplied pre-configured and is suitable for all types of gas turbine engines.

The IAC Aquarius system has been selected by engine manufacturers and both military and commercial aircraft operators as the premier graphical display for aero-engine testing.

Features of the ADAS

• Colour monitors displaying the condition of the engine and facility in analogue, digital and graphical formats
• An on-screen annunciation panel to monitor all critical engine and facility conditions and alert the operator, both visually and audibly, if any limit is exceeded.
• Current and continuous data logs for all system actions are recorded. Data logs include details such as date, time, operator, engine serial number, action etc. The current data log records data starting from system boot-up and the continuous data log typically records the previous 8000 actions, approximately one weeks worth of engine testing. Log files can then be backed-up and archived for future reference
• A recording capability to log transient data - typically 20 scans/second - allowing on-screen test replays, post-test analysis, archiving etc.
• ARINC data recording capability, typically 50 scans/second (optional)
• A ‘black box’ recording capability to automatically record transient data (typically for the previous10 minutes) for on-screen test replays and post-test analysis in the event of an unexpected engine shutdown
• Steady-state scans can be configured, as required by the customer, for averaged data, typically over a 10-second period
• An on-screen display ‘watch-dog’ facility indicates to the operator that the screen is continuously being updated and that there has been no break in the test routine

It has already received the plaudits of several leading aviation experts:

“The best of its kind I’ve yet seen in Europe” - Bill Burchell, Editor, Overhaul and Maintenance

“I congratulate IAC on producing a fine, state-of-the-art test bed” - Bert Jenkins, Principal Engineer (Test), Rolls-Royce plc.

ENDS

For further media information please contact Sally Davis in the IAC Press Office on + 44 (0)23 9266 1600 sally@theprdepartment.co.uk

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