Simulation of train induced forced wind draft for generating electrical power from Vertical Axis Wind Turbine (VAWT)

Abstract

Singapore’s lack of ideal geographic location and natural resources created the need to generate renewable energy to offset its carbon footprint. The characteristics of the wind in tropical climates, which is turbulent flow in multiple directions, encouraged the use of the Vertical Axis Wind Turbine (VAWT), but the natural wind conditions are not feasible to power the VAWT due to inconsistencies in wind speed and direction. Exploring forced ventilation situations, it can either use a mechanically ventilated exhaust or wind energy recovery from accelerating objects. Mass Rail Transport (MRT) trains, the electrical rail system in Singapore, has high mass while accelerating at high velocity. This is why it is capable of producing large draft of increased air velocity. The simulation results from FLUENT ANSYS show that the forced wind draft is of laminar flow (up to 6 m/s) at the sides of the MRT train and diversifies to turbulent flow (up to 8 m/s) at the front face of the MRT due to the drag force. The laminar flow will enable the wind turbine to accelerate the spin momentum of VAWT supporting a greater energy output. The understanding of the vertical profile of wind speed specifications of wind turbines, has led to an invention of a unique idea of integrating a hydraulic lift in the main body of the wind turbine to maximize its potential of harvesting wind energy at greater altitudes due to increase in wind speed by 6%. From the movement of MRT trains, the energy that can be harvested from wind using a 2kW vertical axis wind turbine is calculated as 600,000 W/year. Based on simulation, with a 5 meter increase in the height of the turbine, the efficiency of power generation increases by 0.2 percent.