How to caluculate the pressure immediately downstream of a sudden expansion

[Amaelle]

Homework Statement

Finding a pressure right downstream a sudden expansion ( the picture of the exercice is joined to the solution attempt)

Relevant Equations

Energy balance equation

Good day All
Here is the first ligne of the exercice that might not be visible
As shown in figure , water (kinematic viscosity of water v=1E-6 m2s-1)flows out of a reservoir with a sharp entrance at A.

My questions is how to compute the pressure pn right down stream the sudden expansion

My attempt:
after calculating the velocity V1 in the first pipline we know that
H pipe1 right down stream=Total energy H1 (of the first reservoir)-minor losses
H pipe2 right down stream =H pipe1-minor losses -distributed losses ((easy to calulate))

But still i have no idea how to find the pressure?
Many thanks in advance!
best regards

 

[Chestermiller]

Homework Statement:: Finding a pressure right downstream a sudden expansion ( the picture of the exercice is joined to the solution attempt)
Relevant Equations:: Energy balance equation

Good day All
Here is the first ligne of the exercice that might not be visible
As shown in figure , water (kinematic viscosity of water v=1E-6 m2s-1)flows out of a reservoir with a sharp entrance at A.

My questions is how to compute the pressure pn right down stream the sudden expansionView attachment 260039

My attempt:
after calculating the velocity V1 in the first pipline we know that
H pipe1 right down stream=Total energy H1 (of the first reservoir)-minor losses
H pipe2 right down stream =H pipe1-minor losses -distributed losses ((easy to calulate))

But still i have no idea how to find the pressure?
Many thanks in advance!
best regards

As a first approximation, why not just use the Bernoulli equation?

 

[Amaelle]

Thanks a lot but we have frictions so we can only use energy balance but still let's consider that we can do it how are you going to handle it?

 

[Chestermiller]

Thanks a lot but we have frictions so we can only use energy balance but still let's consider that we can do it how are you going to handle it?

Transport Phenomena by Bird, Stewart, and Lightfoot, and other texts have analytic expressions for friction coefficients to use in flow geometries like this.

 

[Amaelle]

thanks a lot!