- #1

CCM_CAN

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Example point on the pump curve: 20 psi at 180 gallons per minute.

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In summary, you need to determine the pump curve, the flow rate you'll be using, and the point on the pump curve where you'll be operating. From there, you can use the analysis from the linked article to calculate the possible forces on the system.

- #1

CCM_CAN

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Example point on the pump curve: 20 psi at 180 gallons per minute.

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- #2

berkeman

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Which force on what where? The force of the stream of fluid on something at some distance away from the nozzle? Or some other force? Sorry, but it's not obvious to me from reading your question. Thanks.

- #3

CCM_CAN

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The area I am unsure of is how to use the analysis from the link above with what I know about the pump (pump curve).

- #4

Dullard

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You can safely ignore the 2" hose - any contribution from it will disappear in other non-idealities.

You have to determine where on the pump curve that you'll be operating. That is the point where the pump curve intersects with the 'system curve.' This may be done mathematically or graphically - I'd do it graphically. Absent other information, you can approximate the Cv for a 1" (ID) nozzle at 27. The nozzle curve (that you generate from the Cv) is your system curve. Once you determine that point, you'll know the flow and pressure at the nozzle inlet.

You mention 'tuning' the flow rate. If that's by means of pump speed control, you'll need to generate a new pump curve for each speed and determine the new intersection point; if by means of a 'throttle valve' between the pump and nozzle, you'll need to add the flow characteristics of the valve to your nozzle characteristics to get the system curve.

Assuming that you were using a small (or long) hose, the characteristics of that might also need to be included in your system curve.

- #5

russ_watters

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Do you have a performance curve for the nozzle, or is it just a simple cone?CCM_CAN said:

Example point on the pump curve: 20 psi at 180 gallons per minute.

- #6

CCM_CAN

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Simple cone, linear decrease in diameter from 2 inch to `1 inch.

- #7

russ_watters

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@Dullard gave a good method just before I posted my question. Cv is called a flow coefficient. you can google for the equation, graph it, and see where it intersects the pump curve to get your flow rate.CCM_CAN said:Simple cone, linear decrease in diameter from 2 inch to `1 inch.

Alternately and separately I was plugging values into an orifice flow rate calculator on tlv.com and using a 90% efficiency/discharge coefficient yields the same 27 Cv. You could plug in different values for pressure drop until you hit a point on your curve. It's actually not too far off the point you picked as your sample.

To calculate the force from a pump + nozzle system, you will need to know the flow rate of the pump, the pressure at the pump outlet, and the area of the nozzle. The formula for calculating force is F = PA, where P is the pressure and A is the area. You can use this formula to determine the force generated by the pump + nozzle system.

The pump flow rate and force have a direct relationship. As the flow rate increases, the force generated by the pump + nozzle system also increases. This is because a higher flow rate means a larger volume of fluid is being pushed through the system, resulting in a greater force.

The nozzle size plays a crucial role in determining the force from a pump + nozzle system. A smaller nozzle size will result in a higher velocity of the fluid, which in turn will increase the force. On the other hand, a larger nozzle size will result in a lower velocity and therefore a lower force.

Yes, the force from a pump + nozzle system can be increased by changing the pump speed. Increasing the pump speed will result in a higher flow rate, which, as mentioned earlier, directly affects the force. However, it is important to note that increasing the pump speed beyond a certain point may not significantly increase the force and can also lead to other issues such as cavitation.

Yes, there are several other factors that can affect the force from a pump + nozzle system. These include the type and design of the pump, the fluid properties, the length and diameter of the pipes, and any obstructions or restrictions in the system. It is important to consider all these factors when calculating the force from a pump + nozzle system.

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