Performance gain of a horizontal axis hydrokinetic turbine using shroud

Renewable energy is the alternative to commonly used environment polluting and declining fossil fuels. Kinetic energy of water currents is a highly demanded source of renewable energy and horizontal axis hydrokinetic turbines are one amongst the various devices used to extract this energy. However, the low power density of the technique is an important barrier to its commercialization. While the analytical Betz limit for extracting available kinetic power of water streams is 0.59, a practical power coefficient of 0.45 looks ideal. Although the Betz limit cannot be overcome, a shroud placed around the rotor could increases the C_P. This paper presents results of an experimental work done on two different shrouds to study how much a horizontal axis hydrokinetic turbine gains using shrouds.