Flow rate calculation question

[monet man]

Hello all. I am new to this forum. I am an electrical engineer, and I am working on a system which requires me to calculate a flow rate. Once I know this, I can continue with the design. Since I am an electrical engineer, I have insufficient knowledge of fluid dynamics to know how to set up the necessary equation(s) to compute the needed information. That being stated, I will tell all that I can about the system variables, and hopefully if I have given enough info, I will get some assistance in setting up the equation.

I have a cubic (6-sided) liquid reservoir which will contain hydrochloric acid (30% ~ density 1149 kg/m^3).

The bottom side of this reservoir has a 1" (2.54cm) hose that is used to drain this tank.

The hose is connected to a valve with a sharp-edged opening (orifice coefficient,Co, I assume is 1 (?)) which measures 3/8" (0.9525cm) in diameter.

I need to calculate the time that it will take the tank to drain. For calculation purposes, say that the tank is 1m x 1m x 1m, and the tank is full (height of HCl = 1m).

I feel that the height must be a variable for integration (i.e. dV/dy)...but I also want to know the height of HCl in the tank at any given time (i.e. dV/dt). I have been looking online for the answers all day, but my head is starting to hurt from all of the information that I am finding, and I think that I am making this way too complicated for myself. Any help is GREATLY appreciated.

 

[Highway]

Bernoulli's: http://www.efunda.com/formulae/fluids/draining_tank.cfm

Did you run into this while googling?

 

[BadBrain]

monet man:

Try figuring Bernouli's Equation for youself.

See:

http://www.engineeringtoolbox.com/bernouilli-equation-d_183.html

 

[gsal]

This matter has also been discussed a few times in this forum...here is https://www.physicsforums.com/showthread.php?t=507578"

 

[alphy]

I would suggest approaching this problem by first understanding the basic principles of fluid dynamics. The flow rate of a liquid is determined by the Bernoulli's equation, which takes into account factors such as the fluid density, pressure, and velocity. In this case, the velocity of the liquid flowing through the hose can be calculated using the equation Q = A * v, where Q is the flow rate, A is the cross-sectional area of the hose, and v is the velocity of the liquid.

To calculate the velocity, you will need to consider the pressure difference between the top of the tank and the end of the hose, as well as any losses due to friction or changes in elevation. This can be done using the Bernoulli's equation, which states that the total energy of a fluid remains constant throughout the system.

In addition to the Bernoulli's equation, you will also need to consider the continuity equation, which states that the mass flow rate of a fluid remains constant throughout the system. This equation can be used to calculate the height of the liquid in the tank at any given time.

Once you have a better understanding of these principles, you can use them to set up the necessary equations and solve for the flow rate and time it will take for the tank to drain. It may also be helpful to consult with a fluid dynamics expert or refer to textbooks or online resources for further guidance.

In conclusion, while it may seem daunting at first, with a solid understanding of fluid dynamics principles and equations, you should be able to accurately calculate the flow rate and time for your system. Good luck!