Problem Statement (Good luck…): Using Saint-Venant’s Principal and its importance to the analysis of stress acting on a volume element within a body and finite element theory, why is it “technically” incorrect and unrealistic to apply a point load while running a finite element simulation?

Steam, initially at 700 lbf/in.², 550°F undergoes a polytropic process in a piston–cylinder assembly to a final pressure of 2200 lbf/in.² Kinetic and potential energy effects are negligible.

Determine the heat transfer, in Btu per lb of steam, for a polytropic exponent of 1.4,
(a) using data from the steam tables.
(b) assuming ideal gas behavior.

The volume of 1 kg of helium in a piston-cylinder device is initially 7 m3 . Now helium is compressed to 3 m3 while its pressure is maintained constant at 150 kPa. Determine the initial and final temperatures of helium as well as the work required to compress it, in kJ. You may assume deal gas behavior.

A compression spring has a diameter of 0.67 in and a coil diameter of 0.067 in, with 30 total coils.
The spring is to be made of unpeened HD A227 wire and have squared and ground ends. Find the
fatigue factor of safety when repeatedly cycled from 0 to 10.3 lbf. Use the Gerber fatigue criterion
and the Zimmerli data.

An insulated steel pipe carries hot water at 80 ºC. The outer surface of the insulation loses heat to the environment by convection and radiation. For convection, assume hconv = 5.8 W/m2.ºC. The emissivity of the insulation is 0.88 and conductivity, k = 0.038 W/mK. The surroundings are at 30 ºC. Assume the inner surface of the insulation is at the water temperature. What is the surface temperature of the insulation?

Consider the impact of compression of the air-fuel mixture on turbulence. Assume that an idealized turbulent eddy is represented by a gas disc 3 mm in diameter, d, and 0.5 mm thick, l, at atmospheric pressure and temperature. The disck is spinning around its axis at 1000 rpm. What is the rotational speed of the disk after it is adiabatically compressed to 25 atm pressure? The gas disc is compressed equally in both the radial and axial direction; that is d₁ / d₂ = l₁ / l₂. Discuss the results in terms of turbulence in engines.

Use the contact power theory to predict the maximum gas pressure drop (in inches of water) across a scrubber which must be designed to achieve 97% efficiency. Given: Gas Flow rate = 8000 acfm Liquid Flow rate= 60 gal/min Liquid inlet pressure= 50 psi Alpha= 1.31 Beta= 1.12

Calculate the vapour pressures of n-hexane and n-decane above a mixture at 25◦C containing 2% n-C6H14 +98% n-C10H22, by volume. Assume that the densities of pure n-hexane and n-decane are 660 and 730kg/m3, respectively and that the liquids behave ideally.

What is the difference between a two-wire and three-wire motor control circuit?

One method for reducing the pumping work in throttled spark-ignition engines is early intake valve closing (EIVC). With EIVC, the inlet manifold is held at a pressure pi, which is higher than the normal engine intake pressure pi*. The intake valve closes during the intake stroke. The trapped fresh charge and residual is then expanded to the normal cycle (lower) intake pressure, pi*. You can assume that both cycles have the same mass of gas in the cylinder, temperature and pressure at state 1 of the cycle.

a) Sketch a p-V diagram including both the standard and EIVC cycle. On the p-V diagram, shade the area that corresponds to the difference of pumping work between the standard and EIVC cycles.

b) What value of intake pressure pi and VEIVC will give the maximum reduction in pumping work for the EIVC cycle?

c) Derive an expression for this maximum difference in pumping work between the normal cycle and the EIVC cycle in terms of pe, pi*, Vc and Vm. Justify any assumptions you make.

1. Where are stress concentration produced and what design and manufacturing procedures reduce stress concentrations?

2. How do ductile and brittle materials differ in their response to tensile loads when a stress concentration is present?

Give three different friction models or equations and examples of when each is valid.

MEMO

From: The Boss of the comapany

Subject: New Internet Cable Tension Machine installation Issue

Action: Your recommendation with detailed analysis and guidelines are required.

HINT: The question is worded like a businessman would write to you. There is more information than you need, ignore the fluff and focus on the objective. You should be able to do this in 10 minutes.

I received an urgent call this afternoon from our senior field service team leader Chuck R onboard the Japanese vessel K1. The vessel is dedicated to Internet cable installation in the ocean. This field service team is currently in charge of the installation of our new tension machine onboard the vessel. Chuck has indicated that they are in the final testing stage for our customer final acceptance test of the entire system. He is very stressed because this final acceptance test approval is tied to about $2.5 Million dollars payment. He needs our support.

Chuck has indicated to me that during the final test, the system computer screen (AKA Man Machine Interface, MMI) that is connected to the system controller that displays all the system parameters to the operators, indicates the correct tension up to the maximum rating of the machine of 100 KIP and was calibrated to this rating. The system controller has a 12-bit ADC resolution. However, when the system testing exceeds the machine rating, the MMI displays crazy tension numbers. Normally, the system MMI should display 1 KIP resolution.

In addition, Chuck told me that our new programmer on the team, Roger has diagnosed the problem and indicated that the load cells needs to be upgraded to higher capacity load cells. This is of course a showstopper. New load cells units cost only about $5000, but the helicopter cost is about $60,000. Chuck is not sure about the electronics and the digital issues but he thinks that no additional mechanical engineering or manufacturing is needed in case we decide to upgrade. We still need to check with the entire engineering group. However, he is sure that each load cell is connected to a signal conditioning electronic card that outputs 0-10 DC volt to the system ADC. Each card has adjustable knobs, one for zero percent and the other for span (100%).

As you know we are all off for the holidays next week, however I will dispatch the entire engineering group back to the office if I have to, but I need your analysis before I do that since you’re the only engineer on the premises today.

Chuck also indicated that Roger told the customer to apply 0-100 KIP force on the machine while he was calibrating the controller program to display the correct reading.

Our tension machine capacity is rated at 100KIP. However, our mechanical and manufacture design has 200% safety margin, we must not operate at that upper limit of course, but we should be able to operate and display above the machine rating within a reasonable limit. Our standard is twenty percent above the rating.

FYI, the machine has two load cells (SPWE-CA-50K) installed to measure the total tension. One installed on the starboard side and the second installed on the port side of the machine. Their total readings represent the total tension on the machine.

I included the load cell manufacture link below.

I need your recommendation with detailed analysis and guidelines to the field service team.

https://www.800loadcel.com/load-cells/pancake-shear-web-load-cells/spwe.html

The face of a dam is vertical to a depth of 6m below the water surface and then slopes at an angle of 30◦ to the vertical. If the depth of the water is 15m, specify completely the resultant force per meter run acting on the face of the dam.

Poiseuille flow describes laminar flow in a circular pipe. The velocity distribution in such flow has a parabolic form. Prove that the mean velocity is equal to one-half of the maximum velocity in this type of flow. Be sure to show all of your work. (Hint: the analysis is similar to that done for laminar flow between parallel plates)