Engineering Aspects of the European Transonic Windtunnel

Abstract

This paper will review several aspects of the ETW design which are unique and have been specially developed for this application.

The design of the high speed leg components (Fixed Contraction, Supersonic Nozzle, Test Section, Model Carts, Second Throat, High Speed Diffuser) was based on very stringent specifications regarding deflection of flow liner under thermal and pressure induced loads. ETW specifications are of a very high standard in terms of flow quality and call for a very stiff structural arrangement, however ETW has as well been designed for a high productivity and flexibility. The need to perform cooldowns from ambient temperature to less than 100 K in three hours and to perform short range temperature changes (± 40 K) in a few seconds without affecting the dimensional stability of the whole high speed leg has led to very specific design features. The tight control requirements of remotely actuated walls and model support had also to be integrated in the design. This paper gives an overview of the different subsystems involved.

The concept selected for housing the drives and actuators is to have all actuation systems in thermally conditioned boxes (about 50 actuators altogether). A number of design aspects had to be looked at such as the thermal break between warm and cold environment, and various heating and cooling concepts have been selected depending on the local constraints.