VertSLD - Prospecting for the Construction of a Vertical Icing Wind Tunnel for Experimental Simulation of Icing by Supercooled Large Droplets

The exploratory project VertSLD investigates both the physical feasibility and economic viability of an icing wind tunnel concept which avoids many of the difficulties that arise in existing icing wind tunnels when the size of the water droplets exceeds a few hundred microns. in this new concept the "flight path" of the drops within which they are supercooled is arranged vertically and not horizontally.

Short Description


Experimental simulation of SLD droplets distributed homogeneously in the measuring section is difficult to realise in a horizontally oriented measuring section for various operating conditions. Additionally, it is necessary at high flow velocities for the unsprayed droplets to have a sufficient distance in order for them to supercool.


  • To perform a survey of the status quo in relation to existing SLD-capable icing wind tunnels.
  • To assess scientific and market potential.
  • To perform a physical analysis of the concept and cost estimation for the construction, instrumentation and operation of the icing wind tunnel.


Institutions are arising in Europe especially, but also worldwide, which are suitable for experimental simulation of SLD icing, and accordingly, which offer these tests to customers in their service portfolio. 

At this point, it is not only major institutions that are of interest for this project, but also small ones, such as, for example, those operated at universities and other research facilities, as the current project is also applicable to relatively small installations. In this context, the accessibility and pricing of an existing facility for customers or other research groups should also be included in the analysis. 

Based on the knowledge gained and the consortium's many years of experience in operating and marketing icing wind tunnels, the need for a small icing wind tunnel designed specifically for SLD simulation has been identified. 

Estimating the necessary space requirement of the installation, depending on the desired size of cross-section measurements and operating range, i.e. the "environmental conditions", to be covered; the latter are mainly determined by air velocity, air temperature, liquid water content, ice water content and droplet size distribution.


  • Analytical calculations and numerical flow simulations.
  • Development of an icing wind tunnel analysis tool.
  • Market research.
  • SWOT analysis.


  • To evaluate market conditions and scientific potential.
  • To determine required installation space of the tunnel and perform cost estimation.
  • To estimate economic and scientific potential of a university vertical SLD icing wind tunnel.

Project Partners

Funding program: TAKE OFF