Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
REVIEW OF THE TRANSITION PHENOMENA OVER SWEPT WINGS
Submission Author:
Odenir de Almeida , MG , Brazil
Co-Authors:
CAIO ROBERTO BOTTER, Odenir de Almeida, João Paulo Eguea, Fernando catalano
Presenter: Odenir de Almeida
doi://10.26678/ABCM.COBEM2023.COB2023-0371
Abstract
The drag force is ultimately linked to the aircraft performance, as it is inherited from the interaction between the airflow and the body. For conventional and commercial airplanes, although the wing is an aerodynamic device due to its usually low drag coefficient, if it is compared to other kinds of bodies, it is responsible for a huge portion of the airplane total drag. Since the drag is an effort that opposes the aircraft movement, it will impact the net thrust and the fuel consumption. Thus, it is of utmost desire for researchers and aircraft developers to decrease this aerodynamic force. However, working with the wing shape to reduce its drag has its limitations and other alternatives have been studied in the last years to reduce the drag via passive or active boundary layer control. The boundary layer, depending on the flow conditions and the body characteristics, it can start in a laminar regime and transition to a turbulent one. This matters for the drag study because at the laminar regime the boundary layer is thinner resulting in a less draggy characteristic if compared to the turbulent one. Therefore, methods for predicting and describing this phenomenon have been studied via numeric-computational, wind-tunnel testing and even in-flight approaches. The prediction to turbulence is still not fully comprehended so wind-tunnel testing is primordial to the study of the laminar to turbulence boundary layer transition in wings. Methods can couple the utilization of various techniques to either visualize this phenomenon or even quantify it. For this, infrared thermography, PIV, hot-wire anemometry and other techniques may be applied. Therefore, this article has the intention to provide a bibliographic review on the wind tunnel testing works for identifying the transition to turbulence on wings focusing on swept wings as a function of the Reynolds number and the techniques applied for each study. Some original data is also presented in this work. This article then can be used as a base reference that analyses the acknowledgments of each study and may contribute to future works on the subject.
Keywords
Laminar Boundary Layer, infra red thermography, Turbulence, drag reduction, swept wing
