variavel0=<b>Rogerio Fernandes Brito</b> - rogbrito@iem.efei.br Escola Federal de Engenharia de Itajuba
<b>Joao Batista Dias</b> - jbdias@iem.efei.br Escola Federal de Engenharia de Itajuba
<b>Genésio José Menon</b> - genesio@iem.efei.br Escola Federal de Engenharia de Itajuba
<b>Abstract.</b> In this work the laminar mixed convection in vertical elliptic ducts is numerically studied. The flow is unsteady, laminar, developed and without internal energy generation. The fluid physical properties are considered constant except for density in the buoyancy terms for witch the Boussinesq approximation is used. The duct wall is heated with uniform axial heat flux and circumferenttial uniform temperature. The finite element method with triangular elements is used to solve the two-dimensional equations. The average Nusselt number (Nu) and the friction factor-Reynods number product (fRe) are determined as function of Reynolds number (Re), Rayleigh number (Ra) and the semi minor to semi major axis ratio (BA) of the ellipse.
<b>Keywords.</b> Mixed convection, Finite element method, Heat transfer, Numerical methods.