Transonic industrial wind tunnel testing in the 2020s

Abstract

Wind tunnels remain an essential element in the design and development of flight vehicles. However, graduates in aerospace engineering tend to have had little exposure to the demands of industrial experimental work, particularly at high speed, a situation exacerbated by a lack of up-to-date reference material. In an attempt to fill this gap, this paper presents an overview of the current and near-term status and usage of transonic industrial wind tunnels. The review is aimed at recent entrants to the field, with the aim of helping them make the step from research projects in small university facilities to commercial projects in large industrial facilities. In addition, a picture has emerged from the review that contradicts received wisdom that the wind tunnel is in decline. Globally, the industrial transonic wind tunnel is undergoing somewhat of a renaissance. Numbers are increasing, investment levels are rising, capabilities are being enhanced, and facilities are busy.

Impact of Installation on the Performance of an Aero-Engine Exhaust at Wind-Milling Flow Conditions

“…The RANS CFD investigations were based on the DSJP rig (Fig. 1), which will be tested at the ARA TWT [31] in 2023. The DSJP rig was designed to measure the installed suppression effect on the aerodynamic performance of a civil large aero-engine exhaust.…”

“…2.2 Computational Fluid Dynamics Approach. The ARA TWT is an atmospheric wind-tunnel that employs porous walls of the working section [31]. In this work, it was decided to avoid the complexity associated with modeling the effects of wall porosity.…”

“…This work conducted a RANS CFD investigation to quantify the impact of installed suppression on the aerodynamic performance of a civil high by-pass ratio aero-engine exhaust at wind-milling. Analyses were based on the DSJP test rig, which will be tested in the TWT [31] located at the ARA in the UK. The DSJP rig was designed to measure the effect of the installed pressure field on the aerodynamic performance of a civil large separate-jet exhaust.…”

Wind Tunnel Installation Effects on the Base Flow for a High-Speed Exhaust System

“…Such techniques provide important insights into the underlying ŕow physics at the base as well as useful data sets that can be utilized to perform a validation activity against numerical results [28]. However, there are often practical limitations involved in experimental testing of such conőgurations, including the size of the test section of most closed transonic wind tunnels found in academia, which tend to be at the size range of √ 𝐴=0.1-0.25 m as reported by Greenwell [29], where A denotes the test section cross-sectional area. This, along with the relatively large size of the investigated model, usually imposed by instrumentation and necessity for high Reynolds numbers, could lead to large blockage ratios (BRs) and therefore, increased wind tunnel integration effects.…”

“…However, even at this case, severe tunnel integration effects, as those previously mentioned, might signiőcantly affect the ŕow at the base and therefore, lead to erroneous or misleading results with respect to unbounded ŕow conditions. The answer to that question becomes particularly important in the case of university facilities, where transonic closed wind tunnels sit at the lower end of the size range compared to their industrial counterparts [29]. Studies addressing this research question either qualitatively or quantitatively, regarding the potential impact of wind tunnel integration effects on the local base ŕow characteristics, have not been reported in the public domain.…”