TY - JOUR

T1 - Investigating the influence of the jet from three nozzle and spear design configurations on Pelton runner performance by numerical simulation

AU - Petley, Sean

AU - Panagiotopoulos, Alexandros

AU - Benzon, David Shaun

AU - Zidonis, Audrius

AU - Aggidis, George Athanasios

AU - Anagnostopoulos, John

AU - Papantonis, Dimitris

PY - 2019/3/28

Y1 - 2019/3/28

N2 - This paper reports the initial results of three dimensional CFD simulations of the jet – runner interactions in a twin jet horizontal axis Pelton turbine. More specifically, the analysis examines the impact of the nozzle and spear valve configuration on the performance of the runner. Previous research has identified that injectors with notably steeper nozzle and spear angles attain a higher efficiency than the industry standard. However, experimental testing of the entire Pelton system suggests that there appears to be an upper limit beyond which steeper angled designs are no longer optimal. In order to investigate the apparent difference between the numerical prediction of efficiency for the injector system and the obtained experimental results, four different jet configurations are analysed and compared. In the first configuration, the interaction between the runner and an ideal axisymmetric jet profile is investigated. In the final three configurations the runner has been coupled with the jet profile from the aforementioned injectors, namely the Standard design with nozzle and spear angles of 80° & 55° and two Novel designs with angles 110° & 70° and 150° & 90° respectively. The results are compared by examining the impact the jet shape has on the runner torque profile during the bucket cycle and the influence this has on turbine efficiency. All results provided incorporate the Reynolds averaged Navier Stokes (RANS) Shear Stress Transport (SST) turbulence model and a two-phase Volume of Fluid (VOF) model, using the ANSYS® FLUENT® code. Therefore, this paper offers new insights into the optimal jet – runner interaction.

AB - This paper reports the initial results of three dimensional CFD simulations of the jet – runner interactions in a twin jet horizontal axis Pelton turbine. More specifically, the analysis examines the impact of the nozzle and spear valve configuration on the performance of the runner. Previous research has identified that injectors with notably steeper nozzle and spear angles attain a higher efficiency than the industry standard. However, experimental testing of the entire Pelton system suggests that there appears to be an upper limit beyond which steeper angled designs are no longer optimal. In order to investigate the apparent difference between the numerical prediction of efficiency for the injector system and the obtained experimental results, four different jet configurations are analysed and compared. In the first configuration, the interaction between the runner and an ideal axisymmetric jet profile is investigated. In the final three configurations the runner has been coupled with the jet profile from the aforementioned injectors, namely the Standard design with nozzle and spear angles of 80° & 55° and two Novel designs with angles 110° & 70° and 150° & 90° respectively. The results are compared by examining the impact the jet shape has on the runner torque profile during the bucket cycle and the influence this has on turbine efficiency. All results provided incorporate the Reynolds averaged Navier Stokes (RANS) Shear Stress Transport (SST) turbulence model and a two-phase Volume of Fluid (VOF) model, using the ANSYS® FLUENT® code. Therefore, this paper offers new insights into the optimal jet – runner interaction.

U2 - 10.1088/1755-1315/240/2/022004

DO - 10.1088/1755-1315/240/2/022004

M3 - Journal article

VL - 240

JO - IOP Conf. Series: Earth and Environmental Science

JF - IOP Conf. Series: Earth and Environmental Science

SN - 1755-1315

M1 - 022004

ER -