Chapter 8, Problem 25RQ

Two large tanks, each holding 100 L of liquid, are interconnected by pipes, with the liquid flowing from tank A into tank B at a rate of 3 L/min and from B into A at a rate of 1 L/min (see Figure Q1). The liquid inside each tank is kept well stirred. A brine solution with a concentration of 0.2 kg/L of salt flows into tank A at a rate of 6 L/min. The diluted solution flows out of the system from tank A at 4 L/min and from tank B at 2 L/min. If, initially, tank A contains pure water and tank B contains 20 kg of salt. A 6 L/min 0.2 kg/L x(t) 100 L 4 L/min x(0) = 0 kg 3 L/min 1 L/min B y(t) 100 L y(0) = 20 kg 2 L/min Figure Q1 - Mixing problem for interconnected tanks Determine the mass of salt in each tank at time t≥ 0: Analytically (hand calculations) Using MATLAB Numerical Functions (ode45) Creating Simulink Model Plot all solutions on the same graph for the first 15 min. The graph must be fully formatted by code.

5. Estimate the friction pressure gradient in a 10.15 cm bore unheated horizontal pipe for the following conditions: Fluid-propylene Pressure 8.175 bar Temperature-7°C Mass flow of liquid-2.42 kg/s. Density of liquid-530 kg/m³ Mass flow of vapour-0.605 kg/s. Density of vapour-1.48 kg/m³

Describe the following HVAC systems. a)      All-air systems b)      All-water systems c)      Air-water systems   Graphically represent each system with a sketch.