Reference no: EM132960920

Question 1- The force required to maintain the gate of a tank containing a liquid, as shown in the figure, is 23.2 kN. The average pressure over the hatch is measured by a manometer M. The hatch is 1 m deep.

a) If the manometer is a Bourdon tube in C, what is the variation in the angle subtended by the tube if the initial angle (without pressure) is 315° and the constant of proportionality with respect to pressure is 8.1x(10^-5) KPa^-1.

b) If the pressure gauge is a stainless steel, recessed, circular, flat diaphragm device, in which its largest displacement is measured by an LVDT, determine the output voltage Vo, if the diaphragm is 10 mm radius, 0.2 mm thick, Poisson's coefficient (ν) of 0.3 and modulus of elasticity equal to 210 GPa, while the LVDT is an OMEGA LD620-2.5 sensor.

c) If in the manometer of the previous paragraph, instead of the displacement, we measure the forces by means of four iron gauges of nominal resistance 350 Ω and gauge constant 2, connected to a bridge of resistors, fed by a continuous voltage source of 5V, determine what
would be the output voltage if the radial gauges are located at 8 mm from the center and the tangential gauges at 2 mm.

Question 2.- The float of a rotameter has a volume of 520 mm3, with a diameter of 15 mm, as seen by the liquid rising through it, made of aluminum with a relative density of 2.7. The tube of the rotameter has an angle of inclination of 5° and its lower radius is 18 mm. Determine the measuring range for a flow of liquid kerosene of density 0.8 if the float moves a total of 250 mm along the tube. Assume a discharge coefficient equal to 1.

Question 3.- The temperature control in a clothes dryer is done through a copper-iron bimetallic element, 10 cm x 1 mm, whose coefficients of expansion are 17 x 10^-6 °C^-1 and 12 x 10^-6°C^-1, and whose moduli of elasticity are 110 GPa and 200 GPa, respectively.

The heating of the clothes dryer is done through a 0.23Ω electrical resistance, attached to the bimetal and to an insulating block that confines the heat inside, and prevents the heat from escaping to the outside.

The internal temperature of the washer is sensed analogically by a β NTC thermistor equal to 3500, with a nominal resistance of 25KΩ.

The dryer operates at a maximum temperature of 75 °C, controlled by the bimetal. If the convective heat transfer coefficient between the air, inside the dryer and the exposed surface of the switch is 25 W/(K*m²).

How much heating power will be required for the bimetal to operate, if the thermistor reads 30.55 KΩ, at a specific time of operation? Consider that the surface area exposed to heat by the switch is 30 mm².

Attachment:- Pressure gauge.rar