The New Perforated Walls, Compressor and Control Upgrades of the DNW-HST

This paper presents the recently implemented upgrades at the DNW-HST transonic wind tunnel. Renewed industry demand for high-speed testing prompted an evaluation whether the then sixty-year-old slotted wall facility was sufficiently capable and future ready. To achieve better low-supersonic flow simulation a set of perforated walls was introduced. Requirements for supersonic high-incidence testing resulted in modifications to the aft part of the test section and an overhaul and upgrade of the multi-stage compressor to achieve higher pressure ratios. In addition, new data acquisition, model and Mach number control systems were introduced. The new controls, combined with script automated data acquisition now enables faster sweep rates, improved data quality and higher test productivity. With all upgrades commissioned, commercial testing resumed in early 2024. Customers now have the choice of testing in either the slotted or perforated wall test section configuration – with the perforated walls having the edge in terms of blockage alleviation and supersonic wave cancellation performance.