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. In this paper, a comprehensive overview on the design, construction and commissioning of the Braunschweig Icing Wind Tunnel is given. The tunnel features a test section of 0.5 m × 0.5 m with peak velocities of up to 40 m s−1. The static air temperature ranges from −25 to +30 ∘C. Supercooled droplet icing with liquid water contents up to 3 g m−3 can be reproduced. The unique aspect of this facility is the combination of an icing tunnel with a cloud chamber system for making ice particles. These ice particles are more realistic in shape and density than those usually used for mixed phase and ice crystal icing experiments. Ice water contents up to 20 g m−3 can be generated. We further show how current state-of-the-art measurement techniques for particle sizing are performed on ice particles. The data are compared to those of in-flight measurements in mesoscale convective cloud systems in tropical regions. Finally, some applications of the icing wind tunnel are presented.

Photoacoustic hygrometer for icing wind tunnel water content measurement: design, analysis, and intercomparison

“…The PA system was compared against a multi-element water content hot-wire probe (SEA, WCM-2000 Multi Element Water Content System) and an IKP from Cranfield University (CU-IKP; Bansmer et al, 2018), which utilizes commercial NDIR sensor-based hygrometers for simultaneous BWV and isokinetic TW measurement via backward-and forward-facing inlets and was specifically designed for high water content IWT measurement. All probes were mounted side by side on a horizontal splitter-plate-like panel with the probe inlets positioned at the approximate vertical center of the test section (cf.…”

“…Replication of the full SLD, mixed-phase, or high IWC condition envelopes in icing wind tunnels (IWTs) has been largely accomplished by organizations devoted to the experimental simulation of icing environments for the purpose of fundamental icing research and certification of aeronautical components but is associated with a lack of appropriate instrumentation and is still a work in progress for some conditions (Orchard et al, 2018;Van Zante et al, 2018;Bansmer et al, 2018;Breitfuss et al, 2019;Chalmers et al, 2019).…”

Detailed atmospheric ice accretion surface measurement using micro‐computed tomography

“…An airfoil model (Velandia and Bansmer, 2019) was mounted in the test section of the Braunschweig Icing Wind Tunnel (Bansmer et al ., 2018), where icing encounters can be reproduced. Two different ice types were tested reproducing glaze ice and rime ice.…”

Comparison of different droplet measurement techniques in the Braunschweig Icing Wind Tunnel

“…A detailed overview of the Braunschweig Icing Wind Tunnel is given by Bansmer et al (2018). The basic design is a closedloop wind tunnel with a 0.5 m x 0.5 m cross-sectional area at the test section with adjustable velocities between 10 and 40 m s -1 .…”

“…The actuation of the electrically controlled pressure regulators for the water and the compressed air, all valves, and the control unit of the PWM-flow system are integrated into the wind tunnel software, providing the user with remote control of the whole spray system. All aerothermal characteristics, like airflow uniformity, turbulence intensity, and total temperature of the wind tunnel flow, comply with SAE ARP5905 specifications (Bansmer et al, 2018).…”