• Hammer results File doesn't contain any transient extended node.

    Hi, I am new to Bentley Hammer. I am analyzing a Gravity pipeline where water will run from 1619 m elevation to 1400 m elevation in a hilly area with ups and downs. When I check " Transient Results Viewer" it gives a dialogue box. "The hammer results…
  • inserimento air valve dopo evento transitorio arresto pompa (ho bisogno di aiuto)

    buongiorno, dopo tante domande siamo quasi arrivati alla fine del problema. Dopo aver calcolato un'analisi transitoria di arresto di una pompa con numero di giri variabile ho problemi relativi alla cavitazione e quindi ho inserito dove ho questi problemi…
  • evento transitorio spegnimento pompa velocità variabile

    buonasera, ho riscontrato due errori in questa simulazione: 1) problema cavitazione 2) analizzando i risultati dell'analisi ho notato che le portate (flow) delle tubazioni a valle della pompa spenta non tendono mai a 0 ho pensato: per risolvere…
  • modeling a pump start-up transient event in hammer (need help)

    I have an in-line pumping system and I wanted to simulate the pump start-up , I set the problem as in the various examples present in the comunity, but the result of the analysis is "wave speed must be greater than zero". What could be the problem?…
  • Determining the occurrence time for max and min transient pressure at all nodes

    I have carried out transient simulation for an irrigation network. Based on client requirement, I want the occurrence time of the maximum and minimum transient pressures at all junctions. How can we extract this information that at what instant/time we…
  • Como superar o mejorar las presiones negativas en las " presión extrema cabezales"(extreme pressure and heads)

    Hola, tengo presiones negativas en las "presión extrema cabezales"(extreme pressure and heads),el sistema es un modelamiento transitorio en HAMMER(adjunto archivo) Ademas me sale este mensaje 44845 "Con tanque unidireccional" "Pipe" "209" "LINEA…
  • Transient pressure graph in an interior node of the pipe

    Hi, How can I draw a transient pressure graph (pressure data against time) in an interior node of a pipe? Thanks
  • Error: Initial flow is zero, which would result in a discharge coefficient equal to 0, which is not allowed

    Good Afternoon: I am trying to model an irrigation net with a pump, reservoir an irrigation net where all are connected. My particular situation to model is: No demand in any hydrant Pump working from the river to the reservoir Pump shot down…
  • area change modeling

    Hello, how could I model area change in bentley hammer ? Is there any method rather than splitting pipe? does pipe splitting do better simulation for Wave Reflection and Transmission at an expansion and a contraction?
  • Gas volume in hydro-pneumatic tank

    Hello forum, I'm having doubt (due to client "inquiries"), therefore I'm addressing this question to you all. I'm using sealed, gas-law model, hydropneumatic tank element, to model the surge vessel. Total volume is 200m3 and initial gas volume is…
  • Getting reliable results from Bentley Hammer

    Hi, I am modelling a simple system to compare the results to some codes that I have. But, despite having all the configurations similar to codes, I cannot get similar pressure fluctuation. Could you please have a look and let me know the reason? …
  • General Transient Modeling Help

    Does anyone have a good resource for learning and understanding real world transient problems and models? I'm fairly new to transient analyses but I have been through the Bentley training course. I have a couple transient models that I am currently working…
  • Re: transient_hammer analysis inquiry

    Hello Ahmed, I would suggest trying both situations (one valve or two), then compare the results by closely examining graphs and profiles in the Transient Results Viewer (animating a profile path is a great start). This should show you if this arrangement…
  • Re: Split UP

    Hello Sachin, I assume that you're referring to Bentley HAMMER V8 XM or V8i. 1) There are many factors that contribute to the transient results that you see in HAMMER. Basically the configuration of all elements in your model can effect…
  • Re: Hammer calc error

    Velibor, You need to enter the pump inertia. This is needed for a shutdown event, so HAMMER can correctly compute how the pump spins down. It is not needed with a constant speed pump because the pump isn't changing speed. Regards, …
  • 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…
  • Re: Hammer analysis- hydrotank and surge anticipator valve

    Hello, The minor loss coefficient for a hydropneumatic tank is the same standard minor loss coefficient (K) that you can enter for pipes (to represent bends, valves, etc). The head loss through the tank inlet orifice equals K*V 2 /2g , (the standard…
  • Re: Regarding SAV

    Samir, It looks like you're referring to Bentley HAMMER. I believe you should be able to get the discharge coefficient from the valve manufacturer. If it's not available, you may be able to approximate it by back calculating the Cv from the orifice…
  • HAMMER Transient Analysis and Design training course

    Hello subscribers, We will be offering a Live training course on Transient Analysis and Design with Bentley HAMMER on November 26-29, 2012. This 16 hour course is being taught in 4 hour increments over the 4 days, from 11:00 a.m. to 3:00 p.m. EDT each…
  • Re: Modeling a 1.5 second valve closure at Airplane Fueling Nozzle?

    Hello, The pumps are going to operate based on the system conditions (where the pump curve intersects the system head curve.) So, you'll need to "model what you've got" to get the right pump operating point. Meaning, if there aren't FCVs in reality…
  • Re: Modeling Backflow in TCV and FCV

    I assume you're using Bentley HAMMER. When you use a TCV or FCV, a discharge coefficient is calculated based on the head loss through the valve in the initial conditions. This discharge coefficient can be seen in the results section of the valve…
  • Re: Hammer Reservoir Wave Attentuation

    Hello Ryan, When the valve closes, the flow is basically zero. However, the presence of a reservoir (which has a constant hydraulic grade during the transient simulation) may cause small flows in the pipe after the valve is closed. These small…
  • Re: orifice in surge tanks

    Hello Inbarasan, I'm a bit unclear on some of what you said, but I'll try my best to address your questions: "...which is the effective shape in orifice?" The surge tank orifice is assumed to be circular, as you must enter a diameter. If the…
  • Hammer Analysis in Raw Water Transmission System

    I'm trying to evaluate the need for surge protection at new well locations in a raw water transmission system. I have a network of 6 wells all pumping to the water treatment plant. I'm new to Water Hammer and surge analysis so I'm just looking for some…
  • 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…