Resumo:
Azevedo, T. M. (2020): Considering the modality of motor machines, axial hydraulic
turbines are widely used in Brazil and worldwide for hydropower generation; thus, it becomes
essential to dimension these machines, to understand its characteristics, operational criteria and
application on a case-to-case basis. Consequently, the objective of this work is based on
developing a preliminary design of an axial hydraulic turbine, using the theories of grid, wing
lift, potential vortex and radial balance, in order to analyze the project under the numerical and
experimental methods.
Therefore, using classic theories, a rotor preliminary design was developed considering a
constant specific energy distribution from the hub to tip of blade resulting in different blade
assembly angles. The distributor system was designed for the relative velocity to be aligned
with the rotor blade, based on the composition of the velocity triangles at the rotor inlet, for all
the radial positions of the hub to tip of blade. In addition, it was use made a prototype
manufactured in ABS plastic, assembled on the LHPCH test bench, considering the
independent quantities of H, Q and rotation, among the nqA values corresponding to axial rotors.
For the numerical analyzes, the domains, inertial and non-inertial, were discretized with
structured, unstructured and hybrid meshes. For the solution of the RANS equations (Reynolds
Averaged Navier Stokes) k-ω SST turbulence model was used. Thus, the characteristic curves
of the turbine's operation were developed, meeting the criteria of convergence and mesh
independence.
On the other hand, experimental analyzes were carried out using a belt brake to keep the
rotation constant, with variation in flow and head, allowing to elicit experimental characteristic
curves. Finally, comparisons were made between the characteristic curves and efficiency curves
for both methodologies, and even with a small divergence of values, it was possible to validate
both, the preliminary design and the methodologies used in this Master's thesis
