Chapter 3 problem 15

Suppose that in a machining operation of multidirectional FRPs you are getting

high principal (cutting) forces. Which action would you take to reduce the

principal forces? Why?

(a) Reduce cutting speed

(b) Increase rake angle

(c) Reduce depth of cut

(d) Increase clearance angle

(e) All of the above

A frictionless air compressor operates between 200 kPa and 6 MPa. The inlet is at 25°C. Compared to operating adiabatically, what is the energy-input (e.g. power) savings by cooling it with a polytropic exponent of 1.16? Answer in kJ/kg (i.e. kJ of energy saved for every kg of air compressed).

Correct answer is 9.23 kJ/kg; please show steps and thank you!

Rub wool on the Styrofoam cup and hold it over tiny bits of paper on the lab table. What happens to the paper?

Put down some dark paper and a pile of salt and observe the interaction with the charged cup. What happens to the salt?

Consider the fundamental forces: gravity, electromagnetic, as observed with the interactions with salt and pepper. How does this demonstrate the relative strengths (which is stronger?) of these fundamental forces?

Rub the balloon with the wool cloth (or with your own hair). What kind of charge does the balloon acquire? Bring the charged balloon near the bits of paper or salt. Will it “pick up” tiny bits of paper? Yes Observe how distance affects the interactions. What difference does distance make?

Charge it up again and press against a wall made of sheetrock (not brick or stone). Will it stick to the wall? No Go to the sink, turn on the water so that there is a small, steady stream. “Charge up” your plastic tube and hold it close to the top of the stream of water. What happens and why?

Now rub the plastic tube with a square cut from a cooking bag. Write a procedure that you can use to determine if the plastic tube has acquired a net positive or a net negative charge from the cooking bag. (you can use some of the other materials).

Bring the plastic tube charged with the cooking bag near the aluminum can. What happens to the aluminum can when the tube charged from the cooking bag is held near it?

An air-conditioning system operates at a total pressure of 1 atm and consists of a heating section and an evaporative cooler. Air enters the heating section at 15°C and 55 percent relative humidity at a rate of 30 m³/min, and it leaves the evaporative cooler at 25°C and 45 percent relatively humidity. Using appropriate software, study the effect of total pressure in the range 94 to 100 kPa and plot the results as functions of total pressure

What are the main classes of engineering materials?

include the image of an aircraft accident that was caused by failure of a fastener or any image(s) related to the accident. Discuss the following:

• Discuss the details of the accident.
• How did the failure of the fasteners contribute to the accident?
• What could have been done to prevent the accident?

Specify in detail of the joint notation system of the robot used

Any robot from any brand:

1. FANUC

2. Yaskawa

3. Motoman

4. ABB

5. KUKA

how pressure drop relates with heat transfer rate, Reynolds no., nusselt no. and geometry of heat exchanger, please explain and show formulas.

what should be loss of pressure drop and heat transfer okay for best heat exchanger.

how to determine loss of pressure loss

7-9. Give two (2) piping materials with their corresponding schedule # and its application that is available in market today?

10. Give one (1) standard used for piping materials and state one (1) provision regarding that standard?

A beam of steel having square cross section of 20x20mm2

having E =
200 GPa is subjected to an axial (P) load of 20 kN, Torsional (T) load
of 60 Nm and Transverse (F) load of 0.60 kN as shown in Figure. Solve
each load independently for both element A and B existing at the top
and side surface of the beam respectively and determine:
a) State of stress against each load condition for both element A
and B
b) Draw Mohr’s Circle where applicable for each state of stress for
both element A and B
c) Determine the principal planes and the principal stresses,
d) Draw the orientation of the Principal Stresses
e) The stress components exerted on the element obtained by
rotating the given element counterclockwise through 30
degrees.

3. Define critical pressure & discharge pressure for long Laval nozzle convergent-divergent. and What are the practical applications of the long Laval nozzle convergent-divergent

Q4 (a):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 33.77 , wire diameter 5 , and the number of active coils 22. Assume no set removal.

a) Calculate the torsional yield strength,  of the spring wire (in  units). Enter only numeric value upto four places of decimal without units.

(b):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 34.93 , wire diameter 5.87 , and the number of active coils 20. Assume no set removal.

Calculate the static load,  (in  units) corresponding to torsional yield strength,  of the spring wire. Enter only numeric value upto four places of decimal without units.

(c):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 25.5 , wire diameter 4.61 , and the number of active coils 23. Assume no set removal.

Calculate the spring scale,  (in  units). Enter only numeric value upto four places of decimal without units.

(d):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 25.21 , wire diameter 5.91 , and the number of active coils 20. Assume no set removal.

Calculate the deflection,  (in  units) that would be caused by load of part corresponding to . Enter only numeric value upto 4 places of decimal without units.

(e):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 34.76 , wire diameter 5.44 , and the number of active coils 20. Assume no set removal.

Calculate the solid length,  (in  units). Enter only numeric value.

(f):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 27.96 , wire diameter 4.89 , and the number of active coils 21. Assume no set removal.

Calculate the free length,  (in  units). Enter only numeric value upto 4 places of decimal without units.

(g):  A helical compression spring made of music wire (ends are squared and ground) has mean coil diameter 34.27 , wire diameter 4.99 , and the number of active coils 23. Assume no set removal.

Calculate the pitch,  (in  units). Enter only numeric value upto four places of decimal without units.

Consider a steam power plant that operates on a regenerative Rankine cycle and has a net power output of 150 MW. Steam enters the turbine at 10 MPa and 500°C and the condenser at 10 kPa. The isentropic efficiency of the turbine is 80 percent, and that of the pumps is 95 percent. Steam is extracted from the turbine at 0.5 MPa to heat the feedwater in an open feedwater heater. Water leaves the feedwater heater as a saturated liquid. Show the cycle on a T-s diagram, and determine (a) the mass flow rate of steam through the boiler, and (b) the thermal efficiency of the cycle. Also, determine the exergy destruction associated with the regeneration process. Assume a source temperature of 1300 K and a sink temperature of 303 K.

3-) A heat exchanger with 1 body - 4 pipe passages and each pipe (100+ ??) (with a diameter of 2.6 cm each, 4 m long thin wall per pass) will be used to heat the air. Water enters the pipes with a mass flow of 8 kg / s at 350 K temperature, and air enters the body at a temperature of 15 C with a mass flow of 18 kg / s. The pollution factor of the sediment formed inside the pipe over time is 0.0026 m'K / W. Transport coefficients on the inner and outer surfaces of the pipes are estimated at 450 and 200 W / m'K, respectively. Using specific temperatures at 25 ° C for air and water (?? = school no. Last two digits, for example 0611002072; ?? = 72, ie 172 units), a-) the efficiency of the heat exchanger by drawing the shape of the problem, b-) Heat transfer rate ( kW), c-) Calculate the outlet temperatures (C) of the water and air and show the temperatures in the T_L diagram.

28 will be written instead of a question mark

2-) Methane gas enters an uninsulated horizontal pipe with a thin wall of 25 cm in diameter at a temperature of (300+ ??) C with 4.5 tons of mass flow per hour and exits at (280+ ??) C. The pipe is smooth and its length is 10 m and the ambient and environmental temperature is 25 C. Since the smear coefficient of the pipe surface is given as 0.8; (?? = school no. last two digits, for example 0611002072; ?? = 72, ie 300 + 72 = 372 C and 280 + 72 = 352 C) a-) Indoor and outdoor convection coefficients (W / m K), b -) Calculate heat loss from the pipe to the environment (W), c-) Surface temperature of the pipe (C), d-) Calculate the required fan power (W) and interpret the results.

28 will be written instead of a question mark