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…
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…
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…
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?…
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…
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…
Please apply online and feel free to pass this message along to anyone who may have the interest. Thank you!!
https://aquaamerica.wd5.myworkdayjobs.com/en-US/Aqua_America_Careers/job/PA-Bryn-Mawr/Project-Engineer-I_R672-1
GENERAL FUNCTIONS: Build…
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…
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?
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…
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? …
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…
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…
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?
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…
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,
…
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…
How does Hammer determine the pump speed during a power failure event? It's unclear without the input of the a power curve or torque curve how that data is derived. Are these values interpreted some way from the specific speed?
Also, what is the source…
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…
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…
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…
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…
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…
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…