Design, Construction and Commissioning of the Braunschweig Icing Wind Tunnel

Abstract

Abstract. Beyond its physical importance in both fundamental and climate research, atmospheric icing is considered as a severe operational condition in many engineering applications like aviation, electrical power transmission and wind-energy production. To reproduce such icing conditions in a laboratory environment, icing wind tunnels are frequently used. Creating and maintaining a stable icing cloud in the tunnel test section yields different design constraints compared to conventional wind tunnels. In this paper, a comprehensive overview on the design, construction and commissioning of the Braunschweig 5 icing wind tunnel is given. The tunnel features a test section of 0.5m × 0.5m with peak velocities of up to 40m/s. The static temperature ranges from -25• C to +30• C. Supercooled droplet icing with liquid water contents up to 3 g/m 3 can be reproduced. Outstanding ability of the tunnel is to simulate ice crystal icing with natural ice crystals for ice water contents up to 20 g/m 3 . We further show, how current state-of-the-art measurement techniques for particle sizing perform on ice crystals. The data is compared to those of in-flight measurements in mesoscale convective cloud systems in tropical regions. Finally, some 10 applications of the icing wind tunnel are mentioned.

Large-Eddy Simulations of Marine Boundary Layer Clouds Associated with Cold-Air Outbreaks during the ACTIVATE Campaign. Part II: Aerosol–Meteorology–Cloud Interaction

“…The cutoff is 3.5 mm. The twodimensional stereo (2DS) probe (Lawson et al 2006) equipped on HU-25 measures size and concentration of cloud/ice particles in the range of 11.4-1464.9 mm in diameter with a spatial resolution of 11.4 mm pixel 21 (Voigt et al 2010;Bansmer et al 2018). However, the first size bin of 2DS measurement was excluded due to large uncertainties.…”

Porosity formation during atmospheric ice accretion: measurements using micro-computed tomography

“…The simplified model is a bi-dimensional test object. Bansmer and others (2018) provide a spatial calibration of the IWT test section, which proves a uniform distribution of the cloud characteristics. They also explain the droplet generation mechanism, where water is pressurised and injected into an array of industrial two-stage spray nozzle.…”

“…Ice samples were generated in the Braunschweig Icing Wind Tunnel (Bansmer and others, 2018). The samples were extracted and scanned using a micro-computed tomography system (XMT) and a cooling device to keep the ice cold during the scan.…”

Research and Development of a Small-Scale Icing Wind Tunnel Test System for Blade Airfoil Icing Characteristics

“…In the research of the theoretical derivation of icing, the numerical simulation development of icing, and the development of anti-icing systems, the icing wind tunnel test data are important for design and verification basis. Therefore, an icing wind tunnel plays an indispensable role in icing research [5].…”

“…However, there are few reports on the construction of small icing wind tunnels, and only the wind tunnel construction results are given. At present, there is an icing wind tunnel built by the Technical University of Braunschweig [5], and the design, construction, and commissioning processes of the wind tunnel are introduced in detail. However, the wind tunnel structure is relatively complex, and the construction and utilization costs are high.…”