Aplicação de técnica de imageamento térmico na determinação do número de Nusselt em uma placa plana aquecida

• Autor(a) principal: de Almeida, Pedro Paulo Silva
• Data de Publicação: 2020
• Outros Autores: Vila, José Leandro Rivera, Goulart, Jhon Nero Vaz, Nunes, Tallita Karolline, de Melo, Tiago
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Interdisciplinar de Pesquisa em Engenharia
• Texto Completo: https://periodicos.unb.br/index.php/ripe/article/view/28661
• topic: Imageamento térmico. Convecção forçada. Placa plana, experimentação em transferência de calor

Experimental technique was applied to evaluate the thermal field in a smooth flat plate under forced convection. The technique consists in capture the thermal image over different substrates built from different materials and peculiarities. Each substrate was heated by a constant heat source controlled by a power suplly Minipa and the thermal image was captured by a Thermal Camera Fluke™ Ti 125placed 120 mm from the heated pieces. The heated piece was inserted inside an aerodynamic channel whose the free stream velocity U¥ was controlled by a frequency inverter, and therefore, changing the Reynolds number. The experiments were run under ReL up to 6´ 104. The Reynolds number is based on the free stream velocity, the plate length and the kinematic viscosity of the fluid,n. The Prandlt number, based on the molecular diffusion and heat diffusion, n / a - ratio was computed to be 0.70. The outcomes obtained in the experimental campaign successfully described the local Nusselt number as   Nu = C RexmPrn, where C, m and n, were computed as 0.031; 0;85 and 1/3, respectively. In order to maximize the convective heat transfer processes over the conduction we spitted up the flat plate along its length.