Finite Volume Method Numerical Modelling of the Penstock Flows in Dam  Intake Sector Subjected to Varying Operating Conditions with Particle  Image Velocimetry Validation

Nazirul Mubin Zahar; Mohd Hafiz Zawawi; Fei Chong Ng; Mohamad Aizat Abas; Farah  Nurhikmah; Nurhanani Abd Aziz; Lun Hao Tung; Iszmir Nazmi Ismail; Lariyah Mohd Sidek; Mohd Rashid Mohd Radzi

Authors

Nazirul Mubin Zahar Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Mohd Hafiz Zawawi Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Fei Chong Ng School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Mohamad Aizat Abas School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Farah Nurhikmah Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Nurhanani Abd Aziz Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Lun Hao Tung School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Iszmir Nazmi Ismail Department of Mechanical Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Lariyah Mohd Sidek Institute of Energy Infrastructure (IEI), Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor, Malaysia
Mohd Rashid Mohd Radzi Hydro Life Extention Program (HELP), Business Development (Asset) Unit, TNB Power Generation Division, PJX HM Shah Tower, Jalan Persiaran Barat,46050 Petaling Jaya, Selangor, Malaysia

Keywords:

Dam reliability analysis, Finite volume method (FVM) simulation, Intake section, Penstocks, Vortex formation

Abstract

The formation of vortex and swirling in any flow structures of the hydropower dam is undesirable, as it reduced the performance of turbine as well as lowered the efficiency of hydroelectric power generation. Furthermore, it could lead to the hydraulic losses at the entrance of power intakes, the blockage at the trash racks due to entrain debris and the reduction of the working life of turbines. This paper studied penstocks flows in the dam intake section numerically. The dynamics of penstocks flows at different operating conditions were analyzed to determine the vortex formation. To access the veracity of the current proposed numerical model, a validating study based on the particle image velocimetry (PIV) experiment was conducted. It was found the discrepancy between both numerical and experimental flow velocities is 12%, implying the numerical model is well-validated and the corresponding findings are acceptable. It was found that the vortex was formed in the penstock that located at the lowest level relative to other penstocks. Furthermore, the highest pressure of 4 MPa was recorded at the bottom section of the penstock which observed vortex. This numerical work provided useful insights for the future dam reliability analysis, particularly involving penstocks and intake section.