Intake Performance

Introduction

The aircraft intakes perform a crucial role because they deliver the air to the engines. The air flowing into each engine must be well behaved so that the engines operate efficiently and reliably with the minimum possible requirement for maintenance. The intakes must perform their function throughout the operational envelope whatever the speed or attitude of the aircraft.

The Role of Wind Tunnels

Wind tunnel tests are particularly important for the validation of intake designs. The highly complex nature of the airflows involved can be very dynamic with intricate shock systems, often with regions of separation and all within what can be a very small length of highly curved ducting.

Numerical simulation performed on computers plays an ever-increasingly important part in intake design, but due to the highly challenging nature of the airflow, these simulations alone cannot provide the designers with the level of confidence they require to proceed to flight test.

Wind tunnel tests provide the large quantities of high fidelity data needed to quantify the level of distortion and separation in the airflow approaching the engine throughout the operational envelope of the aircraft.

A typical intake test involves the design and manufacture of a model of the front section of the aircraft to be tested. Integrated into this model is an ejector – powered by a supply of high pressure air – which induces the air flow through the intake. An array of measurement probes is used to record pressures and temperatures of the airflow as it approaches the position of the engine inlet. Because of the dynamic nature of the air flow, a high speed data acquisition system is needed to record several thousand data points per second. A data processing suite of programs then converts the recorded data into useful engineering information.

World Class Capability

ARA offers a one-stop service for our customers starting with the design and manufacture of test equipment followed by calibration in our Mach Simulation Tank facility and finishing with a test program in our Transonic Wind Tunnel. We have a world leading capability in responding to challenges set by our customers by developing innovative solutions for the most complex and unique tests.

A Wealth of Experience

Over the past 30 years ARA has completed intake tests for many aircraft development programs including the Tornado, Typhoon, T-50 and the F-35. We have considerable experience in serving international customers and can respond quickly to requirements for out-of-scope tests at short notice.

Excellent Value and Productivity

Our customers receive a service which provides excellent value - comparable with any of our competitors. Very high levels of productivity with minimal down time are made possible by our efficient ejector designs, excellent test program management based on decades of experience and a recent doubling of our high pressure air supply.

Data Acquisition and Processing

Customers who test with us can take advantage of our proven and flexible data acquisition and processing capability. We offer seamless integration of customer supplied code and programs into our in-house data processing suite. Near real-time processing and display of dynamic data allows our customers to make quick decisions based on a reliable data set and adapt their test program as required. This enables a more efficient use of tunnel time creating better value for our customers.

Assured Security of Model and Data

When testing with us, the security of the model and data is assured; we tailor our security measures to suit our customers’ needs. Upon prior request, our highly experienced IT support team can set up Virtual Private Networks (VPN) to permit remote monitoring of test data by customer teams from within and outside the UK.

Flexibility

We operate a flexible service throughout the year to suit the requirements of our customers; we have considerable experience in delivering test programs with 24-hour running.

Technical Information

Data Acquisition:

• 64 channel dynamic data acquisition which can record up to 20,000 data points per second
• Measurement of several hundred steady state pressures recorded at up to 10 data points per second