Company A (2-10 pages) No More Than 10

Put magnetic particles in the material and "make it magnetic" was what our scientist told us. Yet this problem of settling has been hampering our company for a long time. The fluid is magnetic for about 3 minutes and then we have water with a chunk of iron at the bottom... We need to get stable solutions and they are very difficult to find. Please help?

Assignment A
Your report will illustrate how magnetic particles can be added to water to increase the viscosity of the suspension while controlling the settling velocity within the suspensions. Each group is tasked to include the behavior of suspensions that have solid concentrations between 0.01-0.50 volume fraction. In the first part of your report define terminal velocity and settling velocity. Then define the relative viscosity and
apparent viscosity of a suspension. Explain why terminal velocity is used instead of the initial velocity or the velocity before the particles have accelerated due to gravity to the terminal velocity. Then as a measure of the time scales required provide the calculation for the time for each of the following particles to settle 0.1 m for

a.) 0.1,1.0,5.0,10 micron diameter silica sphere in water
b.) 0.25 ,1.0 ,2.0 ,5.0 ,10.0 micron diameter polystyrene sphere in water
c.) 10,20,30,40 micron diameter glass sphere in decane
d.) 50 micron, 500 micron, 1 mm, 2 mm diameter water droplet in air

In the second part of your report discuss each of the following options for use as a magnetic fluid and the drawback of settling. (Assume the density of all of these particles for simplicity is 7900 kg/cubic meters.)

1. Iron Cobalt Nanoparticles (5-8 nanometer diameter) $100/g
2. Magnetite Powder (250-300 nanometer diameter) $10/g
3. Iron Carbonyl Sintered Powders (3-10 micrometer diameter) $1/g

Give values for the viscosity and sedimentation velocity at volume fractions of 0.01, 0.05, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50. Make a table assuming 10 g of magnetic fluid is required for the application or end use. In the table give the the cost per fluid using each of the three options and the volume fractions. Then report on the maximum viscosity, minimum cost, and optimum composition that can be achieved for each particle choice.

Company B (2-10 Pages)

Drilling mud, also known as drilling fluid, is a product used in the process of drilling deep boreholes.

These holes may be drilled for oil and gas extraction, core sampling, and a wide variety of other reasons.

The mud can be an integral part of the drilling process, serving a number of functions. One of the most critical roles of this mud is as a lubricant. Drilling generates tremendous friction, which can damage the drill or the formation being drilled. Drilling mud cuts down on the friction, lowering the heat of drilling and reducing the risk of friction-related complications. The mud also acts as a carrier for the materials
being drilled, with material becoming suspended in the mud and then being carried up the drill to the
surface.

"We need to find a way to formulate a water based mud with components of water, sand (silica), and clay (montmorillionite). We don't need multiple muds so we need a quick way to formulate how the viscosity of this three component mud can be controlled. We will settle for an ideal solution this time, just please help!"

Assignment B

Your report will illustrate a systematic approach to the problem. First you will examine only the sand/water combinations and calculate viscosities and settling times for each. Then you will assume that by adding the clay you create a yield stress that depends on the size of the sand and the amount of clay (which you will assume ideal thickening agent behavior for). Each group is tasked to include the behavior of suspensions that have solid concentrations between 0.30-0.50 volume fraction. In the first part of your report define terminal velocity and settling velocity. Then define the relative viscosity and apparent viscosity of a suspension. Explain why terminal velocity is used instead of the initial velocity or the velocity before the particles have accelerated due to gravity to the terminal velocity. Then define the yield stress. Then introduce the two step solution to the problem being proposed. First calculate the how the viscosity of the sand water mixture changes. Then calculate how the yield stress of the suspension changes if you treat it as a single phase fluid with the viscosity of the suspension and add the clay as a thickening agent.

After your introduction calculate the settling velocity, terminal velocity, and viscosity for volume fractions of 0.30, 0.40, 0.50 of

a. 50 nm Silica ($100/ton)

b. 100 nm Silica ($50/ton)

c. 500 nm Silica ($25/ton)

d. 1,000 nm Silica ($20/ton)

e. 5 micron Silica ($18/ton)

f. 10 micron Silica ($16/ton)

For the above assume a density of 2650 kg/cubic meter. Give values for the viscosity and sedimentation velocity at volume fractions of 0.30, 0.40, 0.50. Make a table assuming 1000 bbl of mud (just sand and water in this calculation) is required for the application or end use. In the table give the cost per fluid assume water is $2/1000 gallons using each of the three options and the volume fractions. Then for the sand/water mixtures report on the maximum viscosity, minimum cost, and optimum composition that can be achieved for each particle choice. Finally treating the suspension as a single component fluid with the viscosity that is the same as the suspension viscosity calculate the yield stress with the addition of a very small amount of clay.