Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Design and construction of a didactic low-velocity wind tunnel
Submission Author:
Arthur Queiroga , DF
Co-Authors:
Arthur Queiroga, Olexiy Shynkarenko, Rhander Viana
Presenter: Arthur Queiroga
doi://10.26678/ABCM.COBEM2021.COB2021-0150
Abstract
Experimental aerodynamics plays an essential role in the development of aerospace structures. It complements numerical simulations and analytical modeling. The primary tool in an empirical study of aerodynamic processes is the wind tunnel. This work's main objective is to design and build and characterize a bench wind tunnel with preferentially laminar flow in its testing section. An open-circuit wind tunnel is a low-cost solution affordable by student research teams. When compared to other types, an open circuit system is smaller, simpler, and cheaper for manufacturing. The following parts compose the tunnel structure: a settling chamber, nozzle, test chamber, diffuser, and a power unit (ventilator). Air enters the settling chamber, where the honeycomb-type flow straightener improves its uniformity. The nozzle influences the flow quality in the test chamber. The nozzle geometry follows recommendations about contraction ratio, length, and shape. In the current work, the polynomial function describes the nozzle surface. A fan with straight blades adds energy to the system. The numerical simulation based on incompressible transient Navier-Stokes equations studies turbulence and viscous effects in the tunnel. The structured three-dimensional mesh used in the simulation takes into account flow gradients. The SST turbulence model validated for low-velocity applications describes the propagation of the boundary layer. The flow straightener's structural integrity is checked, estimating the influence of the pressure and viscous forces. The boundary layer properties and especially laminar-turbulent transition in the tunnel are also studied numerically. As a result of the current work, the wind tunnel project was completed, including the numerical studies on flow quality. Further building of the system will allow validating theoretical and numerical studies. The wind tunnel will study pressure distribution on aerodynamic bodies' surface and low-velocity flow visualization using a smoke machine.
Keywords
Wind Tunnel, Incompressible Flow, Flow Visualization, flow characterization, subsonic nozzle, wind tunnel design, Aerodynamics
