PROCESS CONTROL - EXAMPLE 6.3 : The differential equation is 3 dy / dt + 2y = 1 with y(0) = 1. (a) The Laplace transformation, L for given terms are : L (dy / dt) = sY(s) - y(0), L(y) = Y(s), L(1) = 1 / s. Use such transformation to find Y(s). (b) The initial value theorem states that : When t approaches 0 for a function of y(t), it is equal to a function of sY(s) when s approaches infinity. Use the initial value theorem as a check to the answer found in part (a).

Answer Posted / kangchuentat

PROCESS CONTROL - ANSWER 6.3 : (a) For the equation 3 dy / dt + 2y = 1, its Laplace transformation is 3 [ sY(s) - y(0) ] + 2Y(s) = 1 / s, 3 (sY - 1) + 2Y = 1 / s, 3sY - 3 + 2Y = 1 / s, 3sY + 2Y = 1 / s + 3, Y (3s + 2) = (1 + 3s) / s. Y = Y(s) = (1 + 3s) / [ s (3s + 2) ]. (b) Initial value theorem states that y(0) = sY(infinity), then 1 = s (1 + 3s) / [ s (3s + 2) ] = (1 + 3s) / (3s + 2) approaches 1 when the value of s approaches infinity. The checking is correct. The answer is given by Kang Chuen Tat; PO Box 6263, Dandenong, Victoria VIC 3175, Australia; SMS +61405421706; chuentat@hotmail.com; http://kangchuentat.wordpress.com.

Is This Answer Correct ?    0 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is the Import Procurement Cycle ? and what are the customization steps in SAP ?

5342


How can I treat a waste stream containing both hexavalent chromium and arsenic?

822


Difference between Synthetic foaming agents V/S Protien based foaming agent?

2263


Please help to get IOCL/HPCL or other chemical engineering paper pls send kathir_skv@yahoo.com Regards, kathirvel

2413


MY generator water cooler inlet line height - 11 mtr inlet water line height - 7 mtr water come into the line from overhead tank, O/H tank height - 20 mtr the first tapping in the inlet line is 2" line which down to 4 mtr level plateform., second tapping in inlet water line goes to a pump 6" line installed at 4 mtr level plateform, pump capacity 200m3/hr, head- 30 mtr, hp-40. the outlet of pump of 6" water line connected to a header of 6 mtr long of 6" line, on this header the six tapping are connected, 4 nos. 3" line goes to 11 mtr height water cooler the pressure of the line is 0.15 to 0.25 kg/cm2, 2" and 4" pipe line connected to a cooler at 4 mtrlevel plateform. my question is, at 11 mtr height level the quantity of water and flow is not sufficient for my cooler, the temp. of cooler is rises much more. you are requested to suggest the modification of pipe line/ pump for take more water flow and pressure (desired pressure is 1 kg/cm2)

2047






What kind of concerns is associated with temperature pinch points in condensers?

873


which materials can l use if l want to use length wave 680 to 900 in hplc

1729


Why is post-weld heat treatment (stress relieving) sometimes necessary for welded vessels?

759


Is there a rule of thumb to estimate the footprint of a cooling tower during design phase?

837


What are the various utilities of the process plant?

817


Mention some of the specialized grinding methods?

705


can anybody give me syallbus of chemical engineering for section engineer in railway.

2191


What is fuel requirement of 20kg/hr of incineration having material calorific value 6500 kcal/kg and diesel calorific value 10707 Kcal/Kg (PCC=850 degC and SCC 1050 Deg c)

1426


What step should be taken in process industries if the process variable is oscillating?

2367


How can separation of chiral chemicals affect the chemical and/or pharmaceutical industries?

817