# Find flow rate

## Homework Statement

calculate the flow rate at which oil (kinematic viscocity = (10^-6) (m^2) /s )
flow thru a cast iron pipe 100mm diameter and 115 m long under head difference of 5m

## The Attempt at a Solution

hf = 32μLV / ρg(D^2) how to get the value of μ( dynamic viscosity) ? we need density of oil to get the μ , am i right ? but , density of oil is not given , how to do this ? i plan to get the value of v ( velocity ) and then multiply v with area to get the flow rate

gneill
Mentor
You're only given a few values in the problem statement. Only one is related to the properties of the fluid involved. Did you investigate its definition and perhaps its relationship to the parameters you seek?

You're only given a few values in the problem statement. Only one is related to the properties of the fluid involved. Did you investigate its definition and perhaps its relationship to the parameters you seek?
yes , but i still gt stucked , can somehow guide me how to proceed with this question ?

gneill
Mentor
yes , but i still gt stucked , can somehow guide me how to proceed with this question ?
I'm not an expert in this area. But let's see what we can do.

You presented a single equation in your problem statement: hf = 32μLV / ρg(D^2)

Can you define for me each of the variables in that equation?
What did you discover about the definition of kinematic viscosity?

SteamKing
Staff Emeritus
Homework Helper

## Homework Statement

calculate the flow rate at which oil (kinematic viscocity = (10^-6) (m^2) /s )
flow thru a cast iron pipe 100mm diameter and 115 m long under head difference of 5m

## The Attempt at a Solution

hf = 32μLV / ρg(D^2) how to get the value of μ( dynamic viscosity) ? we need density of oil to get the μ , am i right ? but , density of oil is not given , how to do this ? i plan to get the value of v ( velocity ) and then multiply v with area to get the flow rate
What's the relationship between kinematic viscosity (##\nu##) and dynamic viscosity (##\mu##)?

It should be spelled out in your text. If it isn't, you can look it up:

https://en.wikipedia.org/wiki/Viscosity

What's the relationship between kinematic viscosity (##\nu##) and dynamic viscosity (##\mu##)?

It should be spelled out in your text. If it isn't, you can look it up:

https://en.wikipedia.org/wiki/Viscosity
I noted my mistake, thank you