Equations:

 

Δ----P--

 

+ v----2----2-------v----1---2-

+ g ⋅ Δy = 0

 

ρ

 

 

 

 

2

 

 

 

 

 

 

 

 

 

2

A2

2

 

 

Δ----P--

v2

 

1 – --

A------1--

 

 

+ -------------------

---2-----

---+ g ⋅ Δy = 0

ρ

 

 

 

 

 

 

 

 

 

 

 

 

v1

2



A2

2

 

 

 

 

 

 

 

------

 

– 1

 

 

Δ----P--

+ --------------

------

A-----1-----------------

--- + g ⋅ Δy = 0

ρ

 

 

 

 

 

2

 

 

 

 

 

 

ΔP = P2 – P1 Δy = y2 – y1

 

M = ρ ⋅ Q

Q = A2 – v2

 

 

 

Q = A1 – v1

 

π ⋅

 

D12

 

 

 

A2 =

π ⋅

D22

A1 = -----------------

 

 

 

-------

-4---------

 

 

 

4

 

 

 

 

 

 

 

 

Example:

Given: P2=25_psi, P1=75_psi, y2=35_ft, y1=0_fr, D1=18_in, ρ=64_lb/ft^3, v1=100_ft/s.

Solution: Q=10602.8752_ft^3/min, M=678584.0132_lb/min, v2=122.4213_ft/s, A2=207.8633_in^2, D2=16.2684_in, A1=254.4690_in^2, P = 50_psi, y =35_ft.

Flow with Losses (3, 3)

These equations extend Bernoulli’s equation to include power input (or output) and head loss.

Equations:

M ⋅

 ΔP

+

v22 – v12

 

 

 

--ρ----

---------

--2----------

-- + g

⋅ Δy + hL = W

 

 

 

 

 

 

 

 

 

 

 

v2

2

 A2

2

 

 

Δ----P--

 

1 – --

A-------1--

 

 

 

M ⋅ 

+ --------------------------- -------------

+ g

⋅ Δy + hL = W

ρ

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

v1

2



A1

2

 

 

 

 

-

--------

– 1

 

 

Δ----P--

 

 

 

 

A-----2--

 

 

 

M ⋅ 

+ ------------------ ----------------

+ g

⋅ Δy + hL = W

ρ

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ΔP = P2 – P1

Δy = y2 – y1

M = ρ ⋅ Q

 

 

Q = A2 ⋅ v2

 

 

Q = A1 ⋅ v1

 

 

A1 =

 

π ⋅

D12

 

 

A2 =

π ⋅ D22

 

 

 

-----------------

 

 

--------4---------

 

 

 

 

 

 

 

4

 

 

 

 

 

520 Equation Reference

Page 456
Image 456
HP 50g Graphing, 48gII Graphing manual Flow with Losses 3