In this work was carried out the aerodynamics design of a 1 MW horizontal axis wind turbine by using blade element momentum theory (BEM). The generated design was scaled and built for testing purposes in the discharge of an axial flow fan of 80 cm in diameter. Strip theory was used for the aerodynamic performance evaluation. In the numerical calculations was conducted a comparative analysis of the performance curves adding increasingly correction factors to the original equation of ideal flow to reduce the error regarding real operating values got by the experimental tests. Correction factors introduced in the ideal flow equation were the tip loss factor and drag coefficient. BEM results showed good approximation using experimental data for the tip speed ratio less than design. The best approximation of the power coefficient calculation was for tip speed ratio less than 6. BEM method is a tool for practical calculation and can be used for the design and evaluation of wind turbines when the flow rate is not too turbulent and radial velocity components are negligible.
Within turbine blade rows, particularly for cascades of high deflection angle, cross-channel gradients of steam properties may be appreciable. To determine the effects on spontaneous condensation of gradients of supersaturation normal to streamlines, the conservation equations can be incorporated in a two dimensional calculation procedure. With the help of program FORTRAN 90 a developed computational program of calculations is accomplished, whose results are communicated to the pressure and Mach number distribution, direction of flow and streamlines in the field and the drops distribution in the outlet of the stator blade mesh. The procedure contains a program section, which avoids difficulties in the strongly curved profile of the leading and trailing edge by a developed computational mesh construction.
The combustion products of fuels containing the elements C, H, O, N and S are calculated. The methodology is based on the equations obtained in the stoichiometric balance of atoms. The adiabatic flame temperature is determined considering that the pressure of the boiler furnace remains constant. The scope of this work is limited to the analysis of natural gas (methane) with molecular formula <i>CH<sub>4</sub></i>. The methodology can, however, be employed for the calculation of combustion products of a great variety of hydrocarbons under the established restrictions.In the development of the methodology two cases are contemplated: Φ ≤ 1 (lean and stoichiometric mixture) and Φ > 1 (rich mixture). In the first case it is considered that when the combustion is complete, the combustion products are O<sub>2</sub>, H<sub>2</sub>O, CO<sub>2</sub>, N<sub>2</sub>, SO<sub>2</sub>, and the solution follows directly. When the combustion is incomplete, however, the products H, O, N, H<sub>2</sub>, OH, CO, NO, O<sub>2</sub>, H<sub>2</sub>O, CO<sub>2</sub>, N<sub>2</sub> and SO<sub>2</sub> can be generated, according to Stephen R. Turns, (2000). When bal-ances of atoms are performed, four conservation equations are obtained, one for each of the C, O, H and N elements. An additional restriction requires that the sum of the molar fractions of the products equals one mol. Finally, seven equilibrium constants, corresponding to the seven chemical reactions of combustion, are introduced. All this provides a system of four nonlinear equations which is solved with the Newton-Raphson method
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