Performance of vortex generators as passive snow removal devices for buildings.

Abstract

The objetive of this work is to study the performance of vortex generators as effective passive snow removal devices for buildings in polar climate conditions in order to minimize snow accumulation around buildings. Vortex generators have been successfully used to passively remove snow in fiat terrain like airstrips, but their performance and effectiveness on and around buildings has not been reported. For this purpose, the theory of snow transport and deposition mechanics together with the passive snow removal concept is reviewed; the kinematic variables of this phenomenon are identified, such as the three snow transport processes, the positive correlation between wind acceleration and snow deposition and the necessary wxistence os shear stress to locally remove snow over the surface. The aerodynamic parameters of the vortex generators and delta wing are reviewed, identifying the needed characteristics for building these type of devices. The performance of the vortex generators together with the optimal distance between the obstacle and the vortex generator was determined using a three dimensional simulation solving the Reynolds averaged Navier Stokes (RANS) equations using the SST k-w model incompressible viscous flows through the finite volume method. The simulation results have been numerically verified and a preliminary validation has been carried aout using qualitative results from prototypes currently installed in the Presidente Eduardo Frei Montalva Chilean Antartic Base and with quatitative results from wind tunnel measurements. Wind behaviour around the obstacle was analysed and compared with the kinematic parameters controlling snow deposition, the numerical results are compare3d with experimental data from the Antartic prototypes and wind tunnel experiments. Finally the project is subjected to economic evaluation which aims to demonstrate the feasibility of the installation of these devices.