Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Application of GITT for the characterization of the Thermal Boundary Layer using a non-invasive method with a capacitive sensor
Submission Author:
Fábio Lima , PB , Brazil
Co-Authors:
Fábio Lima, Francisco Belo, Dhiego Veloso, Gustavo Assad, Igor Silveira, Allan Giuseppe
Presenter: Fábio Lima
doi://10.26678/ABCM.COBEM2023.COB2023-0462
Abstract
The thermal boundary layer corresponds to a variation in the temperature field, which occurs in a narrow region next to the wall of a solid body, when it is exposed to a flow of a fluid at a temperature different from its own. Its study is important for several industrial applications, such as designing cooling systems for electrical and electronic components, capturing solar energy, geothermal reservoirs and advanced oil recovery. For the study of the thermal boundary layer (theoretical or practical), authors have presented invasive measurement methods, such methods can mischaracterize this layer, as the contact of the fluid to be analyzed with the sensor can generate inconclusive readings. The present work intends to present a characterization of the thermal boundary layer based on a non-invasive method based on the electromagnetic field model of a capacitive sensor. This sensor consists of two semi-cylindrical copper plates in opposite positions of a borosilicate glass tube. The liquid that fills the inside of a tube in circular shape together with the borosilicate glass tube, becomes the dielectric of the capacitor constituted by the plates, making the sensor response variable according to the characteristics of the liquid that is in it. present inside. The mathematical modeling of the thermal boundary layer will be carried out using the Generalized Integral Transform Technique (GITT), the velocity profile will be considered fully developed at the thermal input, the effects of viscous dissipation will not be considered, impermeability and non-slip on the walls, the body forces will be neglected without generating internal energy and the axial diffusion of the fluid along the flow will also be neglected. The results to be presented will show, from graphics, a detailed characterization of the thermal boundary layer, allowing to verify all its development while the fluid flows through a certain surface.
Keywords
Thermal Boundary layer, Generalized Integral Transform Technique (GITT), capacitive sensor
