• Penstock for 4 turbines

    Hi. I have a problem with a simulation of a 920 meters penstock which feeds four pelton turbines (2 with 0.9 m3/s and 2 with 1.1 m3/s) in my model the pressure of the penstock´s end is 686.92 m H2O and in previous calculations this value should be 258…
  • Modelling a Pelton

    I am modelling a hydro station with 4 pelton units for pressure rise and mass surge. I have currently modelled these as a discharge to atmosphere element as is recommended in the Hammer knowledge base. However, using a discharge-to-atmosphere element…
  • Hammer - Accurate Modelling of a surge Tank

    Hi I am modelling a hydro power station which features an open surge tank. The surge tank is mostly underground and is 7.0 m in diameter, connecting to the main penstock by a 2.5 m diameter, 9.6 m long steel lined pipe which acts as a throttle. My…
  • Hammer V8i - Hydro Power Pump Turbines

    I am currently learning to use this software with the prospect of using it in future projects with clients. Thus far I have modelled standard turbine installations, however I am curious if it is possible to model pump turbines with this software and if…
  • Re: Hammer: Surge Tank Initial Level

    Hi Jesse, thanks for your reply. I do have my tank set up as a junction with no check valve, and as you mention this tank level should follow the HGL. My version is 08.11.03.17 which isn't too old I thought? It seems the steady state isn't accounting…
  • Hammer: Turbine Instant Load Rejection Modelling

    There is one point regarding turbine modelling which is causing me confusion. The instant load rejection scenario requires the turbine to start at 100% gate, is it possible to start at a lower gate opening, as typically the BEP is not at 100% gate. Or…
  • Hammer - Arranging Pipe FlexTable Order

    Hi This may be a silly question, however I have been modelling a hydro station and in setting up the model, when viewing the pipe flextable, the pipes are not listed in sequential order, but in the order which they were added. I understand you…
  • Re: Hammer: Pelton free-surface tailrace surge

    Hi, thanks for your reply. You are correct; I am looking at the pipe carrying the water away. I have attached a basic sketch. I am modelling the pelton as a TCV followed by a D2A so I can have multi-stage valve control. Typically I would only be interested…
  • Moment of Inertia Turbine Input - Hammer

    Hi I am trouble shooting a Hammer model of a hydro scheme which is producing unexpected results. I have some confusion around which inertia Hammer uses. For hydro generation applications inertia is usually given as WR2 or GD2, with GD2 being four times…
  • Hammer - Modelling vertical pipes

    I am modelling a hydro scheme which features a vertical shaft directly at the intake. So lets says the intake is J1 at elevation 100m and drops to J2 at 50m by a 50 m length of pipe before completing a 90 degree bend to horizontal. Whe using the profile…
  • Hammer - Turbine Specific Speed Operating Point

    Hi When calculating the turbine specific speed to use in Hammer, is it more accurate to use the values for P, H, Q & n at the turbine best efficient point or rated point? The specific speed for these two operating points will differ. Kind regards
  • Hammer: Turbine Curve in Relation to Quadrant Curve

    Hi I wish to clarify how the Turbine Curve should be sourced for inputting into Hammer in relation to which quadrant curve is being used. I understand the Quadrant curve is defined by the selection of the specific speed. In my case, I am picking a…
  • Hammer: Pelton free-surface tailrace surge

    Hi I am currently modelling a number of pelton hydro station layouts. One option may (to be confirmed) include a tailrace tunnel with a free surface. Because the tail race tunnel is so long, surges upon start-up are a concern as could flood the pelton…
  • Hammer - Setting gravity

    Hi I am modelling a scheme which has a gravity lower than the standard 9.81 due to elevation. Is there somewhere in Hammer to set this, as surely the available energy will change?