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Las turbinas helicoidales Gorlov son empleadas para la generación de energía eléctrica a partir de la energía cinética de ríos y corrientes marinas. Esta investigación trató sobre el análisis de la influencia del ángulo de ataque de los perfiles de álabes en el coeficiente de potencia de turbinas helicoidales Gorlov, haciendo uso de la simulación en dinámica de fluidos computacionales (CFD, por sus siglas en inglés). La construcción de un dominio computacional se hizo partiendo del diámetro de la turbina. Como modelo de turbulencia para el modelo matemático se empleó el SST k- . Un estudio de sensibilidad del mallado del dominio indicó como suficientes las mallas de unos 65000 nodos para los cálculos del torque. Los álabes fueron rotados en ángulos de ataque de ±12, ± 9, ±6 y ±3º; posteriormente, se valoraron los coeficientes de potencia o rendimiento de la turbina para cada caso. Se determinó la influencia del ángulo de ataque del álabe de turbinas helicoidales en el coeficiente de potencia, como mejora de su rendimiento. Los resultados mostraron variaciones en el rendimiento de la turbina conforme cambiaba el ángulo de ataque; siendo de 6º el ángulo de ataque con el que se obtuvo mayor rendimiento

Electric scooters are used as alternative ways of transport because they easily make travel faster. However, the batteries can take around 5 h to charge and have an autonomy of 30 km. With the presence of the hydrogen cell, a hybrid system reduces the charging times and increases the autonomy of the vehicle by using two types of fuel. An increase of up to 80% in maximum distance and of 34% in operating times is obtained with a 1:10 scale prototype with the hydrogen cell; although more energy is withdrawn, the combined fuel efficiency increases, too. This suggests the cell that is used has the same behavior as some official reported vehicles, which have a long range but low power. This allows concluding that use of the cell is functional for load tests and that the comparison factor obtained works as input for real-scale scooter prototypes to compete with the traditional electric scooters.

The accumulation of particles in a turbulent flow of incompressible air with mono-dispersed solid particles inside a 90° pipe bend was simulated using ANSYS® Fluent (CFD), taking into account the effect of gravity, drag force and a bidirectional fluid-particle coupling. An analysis of the geometrical parameters and the structures of the secondary flow generated in a curved pipe (Dean vortices) was developed, thus determining the characteristic time scales of the flow. Four Stokes numbers (Stk) were formulated, whose values are calculated and studied from the numerical simulations performed. Two different particle sizes (d1 = 50 μm y d2 = 150 μm), at two different flow conditions (Re1 = 61,500 y Re2 = 173,972), and for three curvature ratios Rc/R = 1, 4 and 8 were studied. The flow was solved using a Eulerian–Lagrangian approach with a RNG k-ε turbulence model. Once the multiphase flow was solved and validated, the distribution and maximum particle concentration inside the 90° bend were presented. Additionally, the Stk numbers were calculated to estimate the possible particle concentration level for the different system configurations (dp, Re and Rc/R). It is concluded that, if all Stk numbers are less than one, relative concentration levels reach a minimum, while for Stk numbers larger than one, an increase in the maximum concentration inside the pipe bend was noticed.

In the present study, through Computational Fluid Dynamics techniques, the performance characterization of a new Stairmand-type separator cyclone was carried out using the commercial software ANSYS Fluent. Four models for the geometrical cyclone separator were built, namely model A as per the dimensions reported in the literature and models B, C, and D by applying square and circular shape cavities as a passive flow control technique on the surface of its cylindrical section. The Navier-Stokes equations with the RSM turbulence model were formulated to solve the continuous phase of the cyclone separator and, the Lagrangian approach was adopted to track the solid particles with one way-coupling. The proposed model’s separation efficiency and pressure drop were compared against those recorded in the previous studies reported in the literature. Model D was the cyclone separator that stood out as the most valuable by demonstrating a separation efficiency and pressure drop decrement of 0.42% and 6.01%, respectively.

The constant advance in the development of piezoelectric materials for energy harvesting has demanded new implementations in the electronics field. The piezoelectric property of these materials has been considered an energy source for low-power devices; nevertheless, the units that provide energy are usually adapted to just one piezoelectric device. This aspect complicates the process, taking into account the amount of time needed for an energy harvest; therefore, this research inquired at first into the adequate piezoelectric materials for carrying out the current study. Afterwards, an energy management unit was designed, considering the connection between some modules and allowing the sourcing of an electrolytic cell for producing hydrogen and, in turn, energy. The results evidence a decrease in time charging of the energy storage unit, which allows a cell’s supply of energy in shorter time intervals, its design efficiency being about 90%, in such a way that the energy harvested through the piezoelectric devices can be used in a better manner.