Aluminum fins of triangular profile are attached to a plane wall whose surface temperature is 100°C. The fin base thickness is 2.0 mm, and its length is 10 mm. The system is in ambient air at a temperature of 20°C, and the surface convection coefficient is 40 W/m2·K. (a) What are the fin efficiency and effectiveness? (b) What is the heat dissipated per unit width by a single fin?

(a)nf=

ef=

(b)q'f=

A brick wall 25cm thick, initially at 80°C has a medium at 15°C suddenly placed in conatct with both of its surfaces through a heat transfer coefficient of 90W/m2°C. Find the temperature at a point 2.5cm from the surafce after 10hrs have elapsed. Find also the heat that has flowed out of the wall during that time. Take ρ = 1602kg/m3, cp = 0.84kJ/kg°C, k = 0.69W/m°C,and α = 5.2×10-7m2/s.

The San Bruno pipeline explosion (the case in our first lecture) occurred at 6:11 pm PDT on September 9, 2010, in San Bruno, California, a suburb of San Francisco, when a 30-inch (76 cm) diameter steel natural gas pipeline owned by Pacific Gas & Electric (PG&E) exploded into flames in the Crestmoor residential neighborhood 2 mi (3.2 km) west of San Francisco International Airport near Skyline Boulevard and San Bruno Avenue.

“The (investigation) report concluded that poor pipeline welds went undetected because of a lack of inspections by the company and inadequate monitoring by state and federal regulators. The utility also lacked a workable emergency response plan that board members said could have helped to prevent the devastation in the city of San Bruno.”

"This represents a failure of the entire system — a system of checks and balances that should have prevented this disaster," said Robert L. Sumwalt, an NTSB board member. "The seam weld may have been the technical reason, but this was an organizational accident."

“Even though PG&E is a Local Distribution Company (LDC), a gas utility - and not primarily a midstream company - there were plenty of lessons to be learned by everyone, upstream, downstream, and all points in between. The investigation showed a myriad of events that led up to the catastrophe but a huge discovery was that PG&E and subsequently, many LDC's in the US, could not locate adequate records of their pipelines. Some did not even have emergency plans in place. Important records that were missing included type of pipe, when and where the line was installed, welding inspection reports, coating reports, in-line inspection histories, operating pressure changes, and more. All this data is critical to correctly operating and maintaining a steel pipeline. It was learned that some LDC's could not even locate some of their pipeline assets!”

Based on the above description and your knowledge about “Pipeline Integrity Management”, please :

1) identify the problems in the PG&E’s pipeline management from above description;

2) give your recommendations (at least FOUR items) to the PG&E to prevent similar failures happen again in the future.

Determine the rate of convection heat loss from both the top and the bottom of a flat plate at Ts = 80°C with air in parallel flow at T? = 25°C, u? = 3 m/s. The plate is t = 1 mm thick, L = 25 mm long, and w = 50 mm deep. Neglect the heat loss from the edges of the plate. Compare the rate of convection heat loss from the plate to the rate of convection heat loss from an Lc = 50­mm­long cylinder of the same volume as that of the plate. The convective conditions associated with the cylinder are the same as those associated with the plate.

ANSWER: 5.84 W, 3.73 W

Approximately spherical particles of diameter 150? and density 2650 kg/m3 settle through a liquid of density 1097 kg/m3 and dynamic viscosity 3.8 mPa s. The volume fraction of particles is 30% in a container of internal diameter 2 cm

Calculate: a)The absolute settling velocity that is apparent to the stationary observer in the lab frame. b)The slip velocity (Us) between solid and liquid phases. c) The superficial velocity of the particles in the lab frame.

10 kg of steam is contained at 10 bar in a rigid vessel of volume 2.275 m³. The vessel is cooled until the pressure in the vessel is 7 bar. Calculate the amount of heat removed from the steam.

A spring with a mass of 1 kg has damping constant 10 kg/s and a spring constant 41 kg/s2 . If the spring begins at equilibrium position and is given a velocity of 2 m/s, find the position of the mass at any time t. Is this overdamping, critical damping or underdamping?

500 g of saturated liquid water is contained in a piston-cylinder arrangement. The inside diameter of the cylinder is 100 mm. The water is heated at a constant pressure of 150 kPa until it becomes saturated vapor. Determine (a) the distance through which the piston is raised, and (b) the amount of energy transferred to the water

Octane is to be pumped in a piping system that is routed from storage tanks to the main pump by a number of smaller pumps. One such arrangement is shown below. This pump must supply 0.4 m3 /s of octane to the main pump. All fittings are flanged; the pipe is wrought iron, schedule 80, 2 nominal, with L=65 m. The absolute pressure at section 2 is 282.5 kPa. Determine the power required to be transferred to the liquid. Assuming the overall pump-motor efficiency is 65%, determine the input power required by the motor.  Sch 80, 2 Nom: ?? = 5.252 ????, ?? = 0.00015 cm.  Octane: ?? = 701 ????/??3 , ?? = 0.51 × 10?3 ????/??2

how to do the mechanical design of gas liquid ( flash) separator??
what are the equations used for its mechanical design???

Nitrogen is stored in a large chamber under conditions of 450 K and 1.5x10^5 N/m^2. The gas leaves the chamber through a converging-only nozzle whose outlet area is 30 cm^2. The ambient room pressure is 1x10^5 N/m^2 and there are no losses.

a) What is the velocity of the nitrogen at the nozzle exit?

b) What is the mass flow rate?

c) What is the maximum flow rate that could be obtained by lowering the ambientpressure?

A six-cylinder engine uses pushrods to actuate the valves. The pushrods are 8.0 mm in diameter and are 650 mm long. Suppose the temperature can change from -40^oC to 116 ^oC. If the pushrods are allowed to expand unrestrained, calculate the change in length in mm to two decimal places. Assume they are made from AISI 1040 steel, E = 207 GPa, and have a coefficient of thermal expansion of 11.3 x 10^-6/^oC.

If the pushrods were installed with zero clearance between the parts when at 25^oC, Find the clearance in mm to three decimal points between the parts when the temperature is at -40^oC.

If the pushrods were installed with zero clearance between the parts when at 25^oC, Find the clearance between the parts when the temperature is at -40^oC.

Find the stress in MPa in the rod if the temperature rises to 116^oC.

Commas
Insert commas where necessary in the following sentences. Some sentences, however, may not require commas.

1. Well how are we going to handle this?
2. To avoid any misunderstandings it is important to tell the patient that treatments cannot be successful if appointments are missed.
3. This Wednesday I would like you to go to our St. Louis facility and assist the tech-support team for the remainder of the week.
4. I have some good news for you Amy.
5. In my office the top shelf of the bookcase you will find a revised proposal.
6. Kyle O’Dell our senior mechanic will be assigned to your crew this week.
7. Jim whom I have worked with for two years has the necessary credentials for the position.
8. The assistant behind the counter will be able to answer your questions.
9. Were all the employees able to log on to the network?
10. Charlie on the other hand believes that we should extend the maintenance special through June.
11. Have you had a chance to speak with Kyle Susan and Renee?
12. The packet includes two electrical drawings one mechanical drawing and two structural drawings.
13. The revision plans for the McFarland project are due today and we need to be sure that the corrections have been made.
14. The dedicated competent employee was recognized for her achievements.
15. We are now using the RFI form.
16. Our assignment will be challenging but exciting.
17. Jim you are planning to apply for the ADDA Scholarship aren’t you?
18. Last Monday I completed the mechanical drawings; last Thursday the electrical drawings.
19. “Kristina, your assistance this week with sterilizing hand pieces and setting up trays was greatly appreciated” said Dr. Moore.
20. On Wednesday November 18 Webster High School students will be visiting our campus.

An air-conditioned zone is at 72°F and 40% relative humidity. The total heating load of the space is 300,000 Btu/hr, out of which 60,000 Btu/hr is latent heating load. To maintain an appropriate indoor air quality 1000 CFM of outdoor air at 30°F and 80% relative humidity is required. Determine:

a) flow rate of supplied air at 25 °F above the zone temperature

b) total heating unit load

c) amount of water required for the humidifier

Please show diagrams in psychometric chart too!! Thank you.

Plot several streamlines (including the stagnation and a few internal and external streamlines) of a 2-D semi-infinite body in a free stream of U = 0.35 m/s, and the asymptotic radius of 50 cm.​

Use MATLAB for plotting and calculations.

- Include the body geometry (stagnation streamline) and choose appropriate streamlines to represent the flow around the objects.

- Include a brief explanation and relevant formulas.