Assignment I PDF

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Assignment 1...

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MECH 430 – Process Instrumentation and Measurement Assignment I Instructions: Make sure to submit a separate VI for each problem. The VI should be named with your AUBnet name (e.g. nk64) followed by the problem number (i.e. nk64_assignment1_problem1). Zip all the files into a single file. The filename should be in the same format as before (e.g. nk64_assignment1). In these set of 3 problems we will try to build a VI that will simulate the flow of water out of a tank through a valve and display the total volume of water remaining in the tank as time progresses. Since the problems are related to one another and add up to build the final VI, you should solve them in sequence. [The schematic of the tank is shown at the end].

Problem 1: There is a tank filled with water. The pressure at the bottom of the tank is a function of the height of water, given by the equation: 𝑃 = 𝜌𝑔ℎ + 𝑃𝑎𝑡𝑚 Where 𝑃 is the pressure in Pa. 𝜌 is the density of water (assume 1000kg/m3) 𝑔 is gravitational acceleration (9.81m/s2) and ℎ is the height of the water in the tank in m (to be specified by the user – assume maximum height can be 10m) 𝑃𝑎𝑡𝑚 is the atmospheric pressure (101325Pa) a) Build a VI that takes the height of the water in the tank as a user input and calculates the pressure at the bottom of a tank and displays it on a numeric indicator. The program should run until the user presses the stop button. b) Add a tank indicator on the front panel to display the height of water in the tank (in addition to the numeric indicator) and a gauge indicator for the pressure. Modify the maximum and minimum values of the tank and gauge indicators to allow for the entire range of values possible. [You can modify the maximum and minimum values by double clicking on the value on the front panel].

Problem 2: For the same tank of the previous problem. Assume there is a valve at the bottom of the tank with an opening area ‘A’. The flow of water coming out of the valve is a function of the pressure and the area based on the following: 𝑄 = 𝐴𝑣𝑎𝑙𝑣𝑒 √2(𝑃1 − 𝑃2 ) ⁄𝜌 Where 𝑄 is the flow rate (m3/s) 𝐴𝑣𝑎𝑙𝑣𝑒 is the valve opening area (m2) defined by the user (minimum opening area is 0m2 and maximum is 0.01m2)

𝑃2 is the pressure (Pa) at the top of the tank (atmospheric pressure: 101325Pa) and 𝑃1 is the pressure at the bottom of the tank (Pa) and 𝜌 is the density of water (1000kg/m3) a) Build a VI that takes the height of the water and the valve opening area as user inputs and calculates the flow rate and displays it on a numeric indicator. The program should run until the user presses the stop button. b) The VI should be such that if the user specifies an area greater than area max, it is limited to area max. And if the height specified is greater than 10m, it is set to 10 accordingly. [NOTE: Use the ‘select’ block found in the block diagram in the ‘comparison’ section to check for the limits].

Problem 3: In this part, we will merge the Vis of problem 1 and problem 2 with some modification. The total volume 𝑉𝑜𝑙𝑡𝑎𝑛𝑘 = 𝐴𝑡𝑎𝑛𝑘 × ℎ (where 𝐴𝑡𝑎𝑛𝑘 = 1𝑚2 ). Knowing that as water starts flowing out of the valve, the volume of water in the tank (starting from a full tank) will drop in proportion to the amount of water flowing out of the valve (Q) which was calculated in the 2nd problem. The height of the water remaining in the tank will become: ℎ𝑟𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 = ℎ𝑝𝑟𝑒𝑣𝑖𝑜𝑢𝑠 − ℎ𝑟𝑒𝑚𝑜𝑣𝑒𝑑 Where ℎ𝑟𝑒𝑚𝑜𝑣𝑒𝑑 is due to the water flowing out which is: 𝑄 × ∆𝑡𝑖𝑚𝑒 ℎ𝑟𝑒𝑚𝑜𝑣𝑒𝑑 = 𝐴 𝑇𝐴𝑁𝐾 Where 𝑄 is the flow calculated and time is in seconds. NOTE: Each iteration of the loop is equivalent to 0.1 seconds. (i.e. 100ms). Build a VI that has 2 user inputs and 2 indicators. The inputs are the height of water in the tank and the opening area of the valve a) Display on a chart variation of remaining height until tank empties (assume that the tank is empty if the height of the remaining water is less than 0.1m). The chart output should look as follows:

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