Calculate Pressure Loss in Kenetic Fluid Energy 180° Reversal

[charlieroper]

Can anyone tell me how to calculate the kenetic energy loss in the pressure of a fluid by forcing it to change direction 180 degrees? I need to know the pressure loss in a single reversal so I can start to figure how many I need. I’ve asked this question of your fluid power engineers, but they tell me it basically boils down to trial and error. But I need a reasonable point at which to start a trial.

I need to lower the pressure of a 9.5 Liter/minute stream of .453 Kg/liter water 280 Kg/cm through a minimum passage area of 3.17 mm. I can’t do this with a single orifice because of anticipated solids in the fluid which would quickly clog such a tiny opening. I wish to harass and hector the fluid as much as possible by passing it through a course of abrupt right angle turns using the fluid’s inertia and other properties to accomplish a series of pressure drops. Is it possible working with this small volume? Does anyone have a reasonably non graduate student level formula which takes into account those factors needed to calculate the pressure losses? Thanks to anyone with the education to size this thing up.

 

[eljose79]

Calculating the kinetic energy loss in the pressure of a fluid due to a change in direction can be a complex task, as it involves several factors such as fluid velocity, density, and viscosity. However, there are some standard equations that can provide a reasonable estimate for your specific situation.

Firstly, to calculate the pressure loss in a single reversal, you can use the Bernoulli's equation, which states that the total pressure of a fluid remains constant along a streamline. This means that the sum of the kinetic energy, potential energy, and pressure energy of the fluid will remain the same before and after the direction change.

P1 + (1/2)ρV1^2 + ρgh1 = P2 + (1/2)ρV2^2 + ρgh2

Where:
P1 and P2 are the pressures before and after the direction change, respectively
ρ is the density of the fluid
V1 and V2 are the velocities before and after the direction change, respectively
g is the acceleration due to gravity
h1 and h2 are the heights of the fluid before and after the direction change, respectively

To estimate the pressure loss in your specific situation, you can use the following steps:

1. Calculate the velocity of the fluid before the direction change using the volumetric flow rate and the minimum passage area:

V1 = (Q/A1)

Where:
Q is the volumetric flow rate (9.5 liters/minute)
A1 is the minimum passage area (3.17 mm = 0.00000317 m)

2. Estimate the velocity of the fluid after the direction change. This will depend on the design of your setup and the number of turns the fluid will go through. You can use a conservative estimate of 50% of the initial velocity (V1) for this calculation:

V2 = 0.5V1

3. Calculate the pressure loss using the Bernoulli's equation:

ΔP = P1 - P2 = (1/2)ρ(V2^2 - V1^2)

Where:
ΔP is the pressure loss
ρ is the density of the fluid
V1 and V2 are the velocities before and after the direction change, respectively

Please note that this is just an estimate and the actual pressure loss may vary depending on the specifics of your setup. If you are looking for a more accurate calculation,

 

[charng]

Hello,

Calculating pressure loss in a kinetic fluid energy 180° reversal can be a complex process, as it involves multiple factors such as fluid properties, flow rate, and geometry of the system. It is not a straightforward calculation and may require some experimentation to find the most efficient solution.

That being said, there are some general equations that can be used to estimate the pressure loss in a 180° reversal. One commonly used equation is the Darcy-Weisbach equation, which takes into account the fluid density, flow rate, and frictional losses in the system. Another equation is the Bernoulli equation, which considers the change in velocity and elevation of the fluid.

However, in order to accurately calculate the pressure loss in your specific system, it is important to have a detailed understanding of the fluid properties and the geometry of the system. This may require the expertise of a fluid power engineer or a thorough analysis using computational fluid dynamics (CFD) software.

In regards to using abrupt right angle turns to lower the pressure, this may not be the most efficient method as it can create additional turbulence and energy losses in the system. It may be worth considering alternative methods such as using a series of gradual bends or a throttling valve to achieve the desired pressure drop.

I hope this information helps in your research and experimentation. It is always best to consult with a qualified engineer or conduct thorough testing to find the most effective solution for your specific system. Best of luck in your project.