Chapter 81, Problem 9CQ

parts e,f,g

Figure 9-6 9-49 An aluminum alloy plate with dimensions 20 cm x 10 cm × 2 cm needs to be cast with a secondary dendrite arm spacing of 10-2 cm (refer to Figure 9-6). What mold constant B is required (assume n = 2 )? Secondary dendrite arm spacing (cm) - 10-1 10-2 10-3 10 41 0.1 1 Copper Zinc alloys Aluminum alloys 10 100 1,000 10,000 100,000 Solidification time (s)

9-72 Figure 9-29 shows a cylindrical riser attached to a casting. Compare the solidification times for each casting section and the riser and determine whether the riser will be effective. Figure 9-29 Т 3 6 3 8 3 6 Details A diagram shows the step-block casting. A cylinder of height "7" and diameter "3" is kept on a platform consisting of 2 steps. The width of the second step of the platform is labeled as "3". The horizontal length of the first step is labeled as "6." The horizontal length, width and height of the first step are labeled "6", "8" and "3".

6/94 Determine the minimum coefficient of static friction for which the bar can be in static equilibrium in the config- uration shown. The bar is uniform and the fixed peg at C is small. Neglect friction at B. A L PROBLEM 6/94 B L 22

Q2. For the following situation, estimate the minimum required compressive strength of 20/40 proppant. If intermediate-strength proppant is used, estimate the permeability of the proppant pack: Formation depth: 10,000 ft Overburden density: 165lbm/ft3 Poison’s ratio: 0.25 Biot constant: 0.7 Reservoir pressure: 6,500 psi Production drawdown: 2,000 and 4,000 psi

A 3-in.-radius drum is rigidly attached to a 5-in.-radius drum as shown. One of the drums rolls without sliding on the surface shown, and a cord is wound around the other drum. Knowing that at the instant shown. point A has a velocity of 4.875 in./sin./s and an acceleration of 15.50 in./s2in./s2 , both directed to the right, determine the accelerations of points A, B, and C of the drums. The cord is wound around the 3 inch radius drum. Point B is at the bottom of the 5 inch radius drum. Point A is at the bottom of the 3 inch radius drum. Point C is on the right edge of the 5 inch radius drum. The accelerations of point B is______  in./s2 . The accelerations of point A is ______ in./s2 ______ ⦨  °. at what angle/direction The accelerations of point C is______  in./s2 ______  ⦪  °. at what angle/direction?

A total volume of mud is 1,000 bbls that has a mud weight of 9.1 ppg. Calculate the volumefractions of water, Bentonite, and the weight of Bentonite used. Density of powder Bentonite is 156 lbm/ft3

A 3-in.-radius drum is rigidly attached to a 5-in.-radius drum as shown. One of the drums rolls without sliding on the surface shown, and a cord is wound around the other drum. Knowing that at the instant shown. point A has a velocity of 4.875 in./sin./s and an acceleration of 15.50 in./s2in./s2 , both directed to the right, determine the accelerations of points A, B, and C of the drums. The cord is wound around the 3 inch radius drum. Point B is at the bottom of the 5 inch radius drum. Point A is at the bottom of the 3 inch radius drum. Point C is on the right edge of the 5 inch radius drum.   The accelerations of point B is ______  in./s2 The accelerations of point A is ______  in./s2  _____⦨  °.  The accelerations of point C is _______ in./s2 ____  ⦪  °.

The average heat transfer coefficent for airflow over an odd shaped body is to be determined by mass transfer measurements and using the Chilton-Colburn analogy btwn heat and mass transfer. The experiemnt is conducted by blowing dry air at 1 atm at a free-stream velocity of 2 m/s over a body covered with a layer of naphthalene. The surface area of the body is .75 m^2, and it is observed that 100 g of maphthalene has sublimated in 45 min. During the experiemnt, both the body and the air were kep at 25oC, at which the vapor pressure and mass diffusivity of naphthalene are 11 Pa and Dab=0.61*10^-5 m^2/s respectively. Determine the heat transfer coefficent under the same flow conditions over the same geometry.