Conventional pelton turbine optimization using Coupled Eulerian Lagrangian technique

Pelton wheel is an impulsive type of water turbine in which the water jet exiting the nozzle impacts the Pelton wheel through the buckets. The energy from the jet is imparted to the buckets causing exertion of torque onto the wheel. The applied torque subsequently rotates the wheel generating electrical energy. An attempt in this analysis is made to simulate the angular rotation of the Pelton wheel through transfer of energy from the water jet. The given problem involves fluid structural interaction and thus, is simulated using Coupled Eulerian Lagrangian technique available in Abaqus. Various parameters like Pelton bucket material, angle of jet incidence, jet impact velocity etc. were varied to effectively optimize the output of the turbine which are further dependent upon the angular speed of the Pelton wheel. Although many other parameters are classified under turbine outputs, in this analysis only turbine angular speed is given primary importance. Pelton wheel buckets are generally manufactured using brass, aluminum or sometimes stainless steel. While these materials are quite economical, they lead to corrosion in the long run. Hence, advance composite materials are used to evade the problem. Also, considering the cost into mind, the material utilization is made thriftily. Plastic strains and stresses are determined for various cases to obtain an idea on best possible material and its corresponding design that produces best results. On the other hand, modification with fluid parameters like its velocity, angle of impact, fluid properties etc. are similarly made to realize best possible results. Similarly, obtained torque is optimized by varying the specified parameters. Eulerian fluid (water in this case) is impacted upon the turbine buckets by a nozzle which injects the water jet at a defined angle and velocity. The eulerian fluid flows in a specific form (shown in figures) upon the buckets due to contact, which is yet again quite pivotal to verify the validity of the simulation. To avoid any further action on the pelton bujckets caused by the free fluid (free fluid in the eulerian domain/mesh after impact), an eulerian boundary condition is imposed on the eulerian domain. No material/fluid from outside can enter the domain and similarly the impacted fluid can exit the domain.