ISO Fluid Processing Lab:  Using Math-Script in LabVIEW

Purpose:  The purpose of this laboratory exercise is to introduce the use and application of math-scripting as a function in LabVIEW.  Math Script allows for embedding formulas or C+ type code as a sub-program and makes programming more efficient when calculations are needed.  To illustrate this application, a fluid pumping station will be created, and time to fill the tank along with other variables will be calculated and displayed on the front panel.

Objectives:  The objectives of this exercise are to allow students to become familiar with the following:

Creating a Math Script structure

Creating INPUT variables

Creating OUTPUT variables

Writing formulas

Displaying required results

Procedures:

Study the system diagram shown in the page 3.  Your system should calculate the following outputs based on given inputs.  A table showing input variables and calculated variables is shown below.

   Input Variables                                   

Nominal Pump Flow Rate (LPM)

Tank Diameter (mm)

Tank Height (mm)

   Calculated Variables

Pump Flow Rate (LPM):  LPM = Nominal – (zero to 10 liters per minute).    

    Note use a random number generator to simulate actual LPM.

LP - Liters Pumped:  Liters pumped = Actual LPM x Elapsed time in       

        minutes.

TV – Tank Volume (cubic meters)

TVL – Tank Volume (Liters)

FL - Fluid Level (mm)

TTF -Time to Fill (minutes)

TTFR - Time remaining to Fill (minutes)

KPa - Head Pressure (absolute KPa)  Note: Assuming water is being pumped.

Note:  Static head pressure can be found by the following formula: 

                     P = weigh density (g) x head (h)  or

                     P =  g  h

           Mass density of water = 1000 Kg / m³

          Weight density of water = 9810 N/m³

General System Operation:  Based on the nominal flow rate of the pump, the area of the tank, and height of the tank (shown in green), the VI should calculate and display the variables shown in yellow below.  If the fluid level in the tank is equal to the vertical height of the tank, the system should automatically shut down.  Note:  Use a 250 ms wait function inside the while loop.

Procedures continued:

A demonstration of math script will be given in class.  You will need to develop the block diagram for the corresponding front panel shown above.  Note up to now you have been given both the front panel and block diagram.  In this exercise, you will be required to develop your own.   Note, it is advisable to hand calculate values to confirm your answers.

Submit a lab report in the usual required format.

Helpful conversions and formulae

10⁶  mm³ = 1 liter

Volume of Tank = Area x Height of Tank

Time to fill = Flow rate x elapsed time

Atmospheric pressure (absolute) = 101 KPa

Head Pressure = weight density in N/m³ x fluid head in meters

Note:  The system shown below represents a fluid processing system in Imperial Units. 
            Your developed system must be in ISO units.

The tank should be animated such that the fluid level in the tank will change (fill) while the pump is running. 
Also, add chart(s) that will display the nominal flow rate, actual flow rate, fluid level, and time to fill.

Fluid Pumping Station Front Panel