Register to reply 
A math or a simple fluid problem? 
Share this thread: 
#1
Jan2906, 11:47 AM

P: 320

Hi all!
I am solving for the height of a tank as a function of time. The tank has a constant inflow of a and is subjected to small fluctuation of bsin(wt). So the inflow is simply a+bsin(wt). The outflow should be proportional to the square root of the height, H. So outflow = c*sqrt(H) Therefore the below differential equation is obtained with k=the area of the tank: [tex]\frac{a+bsinwtc\sqrt{H}}{k}=\frac{dH}{dt}[/tex] but the problem is that I don't know how to solve this ODE... Can anyone solve the problem? 


#2
Jan2906, 01:17 PM

Sci Advisor
PF Gold
P: 1,479

Have you been given this equation or have you set it up by yourself?



#3
Jan2906, 11:13 PM

P: 320

I set it up myself. And I have show my deduction:
The tank has a constant inflow of a and is subjected to small fluctuation of bsin(wt). So the inflow is simply a+bsin(wt). The outflow should be proportional to the square root of the height, H. So outflow = c*sqrt(H) Therefore the above differential appears. Am i correct? 


#4
Jan3006, 08:45 PM

Sci Advisor
PF Gold
P: 1,479

A math or a simple fluid problem?



#5
Feb2106, 01:09 AM

P: 37

this problem really has nothing to do with fluids..its just a math problem..
inflow is a+bsin(wt) correct. outflow you said is proportional to square root of the height, h.. is then right too.. c*sqrt(h)... now if you divide volume by cross sectional area you get height.. im thinking you need to find the radius in terms of height also by rearranged the volume equation... that way your equation will be composed only of H terms. 


Register to reply 
Related Discussions  
Simple math problem, I guess?  Introductory Physics Homework  2  
Simple math problem  Precalculus Mathematics Homework  15  
Help with simple math problem  Precalculus Mathematics Homework  3  
Simple math problem  Introductory Physics Homework  18  
Need help with simple math problem  General Math  5 