Mechanical Engineering

The Francis turbine is an inward flow turbine that is the most efficient and widely used water turbine in the world today. It works best in higher head (pressure) applications, and hydroelectric power plants at big dams use these guys to make lots of watt-hours. The term "inward flow" means that the turbine itself (the thing with the blades that the water "presses on" to make the thing turn) has the water directed from the outside of the turbine wheel in onto the blades, and through them to a "center area" for the water to exit. The unit is darn efficient. Pictures are a mouse click away. Use the link to surf on over to our friends at Wikipedia (from which some of the data here was gathered) for more information and the cool pics that really show a viewer how the unit works.

manufactured wood is man made wood

The only difference between the two is that projection welding requires preparation of the joint members in the way of adding a preformed dimple or projection. Spot welding is used without such preparation to the joint members. it's just heat and pressure.

To find the mechanical advantage of a simple machine divide output force by input

force. (input force is the force that we exert on a machine, and output force is the force that is exerted by a machine).

to allow for the thermal expansion or contraction

1810 Stainless Steel is the European grade that is equivalent to AISI 304 Stainless Steel. It's the most common stainless steel going. Here's the rundown: Fe, <0.08% C, 17.5-20% Cr, 8-11% Ni, <2% Mn, <1% Si, <0.045% P, <0.03% S

To work out the mass of wire you need to know its volume. The wire is circular so that volume would just be the cross sectional area (pi * r^2) multiplied by the length of wire. Lets call the length L.

The equation is then volume = pi * radius^2 * L.

To get the mass of the wire we now multiply this equation by denstiy of the wire; that is how much the wire weighs per volume. Assuming the wire is steel this would be around 800Kg/m^3. So what you want to do is work out the volume as above, then multiply by 800, making sure that your units are consistant....ie lenght and radius in metres.

.1250 inches or 3.18 mm

Mild steel, not copper.

I can vary but it starts around 117,000 psi to 143,000 psi on the Average! Of course higher strength is obtainable depending on Tempering and Heat treating the steel I would use the main two numbers as a reference.

Heat treating of high carbon steel to harden it is an instantaneous process. The steel is heated red hot, causing the formation of crystals of very hard type of Iron Carbide called "Martinsite". If cooled slowly, the Martensite reverts to iron and carbon again and the steel remains soft. But if cooled rapidly by plunging the red hot steel in water or oil, there is insufficient time for the Martinsite to break down to iron and carbon, and it remains as crystals of very hard Martinsite, imparting hardness to the steel.

The primary purpose of flux is "to clean". It mixes with the elements in the molten puddle and removes impurities. As it cools it floats to the surface and creates the slag which prevents Oxygen from attacking the Iron.

In a chilled water system, the chillers are happiest with a constant-volume flow. In a primary-secondary loop system, the chiller has a primary pump that is constant-speed. If that were the only pump, and it circulated chilled water through the chiller and the load (air handler, etc.), imagine what would happen as the temperature setpoint was reached. The control valve starts to close, reducing the flow. This deadheads the pump, which is bad in itself, but it also reduces flow through the chiller. The chiller could be damaged, or it would trip on a low flow safety, or at the very least it operates poorly, or inefficiently. You could change the control valve to a three-way diverting valve. Now instead of closing, upon reaching setpoint the valve diverts some of the flow, bypassing the load, and recirculates it back to the chiller. This maintains full flow through the system, but it wastes energy because you are always pumping full-load flow even in the dead of winter when you may only need a fraction of the system's capacity. What if there was a way to maintain a constant flow through the chiller, yet only supply just the needed flow to the building? Well, let's change the control valve(s) back to standard 2-way, and add a secondary pump with VFD. We will also need a pressure sensor on the secondary loop. We add a bypass pipe between the two pumps. Can you visualize the piping? Water leaves the primary pump, goes through the chiller, heads out on the CHW supply line. Then it can either circulate through the bypass line and back to the pump (that's the primary loop), or keep on going out to the building, then back from the building, through the secondary pump, past the bypass line, and to the suction on the primary pump. The beauty of the primary-secondary system is we can reduce secondary flow to the building as the cooling load reduces. As the control valve(s) close, the pressure in the secondary loop rises. The pressure sensor detects this and slows the pump down to maintain a constant pressure. As less and less water flows from the chiller out to the building, more and more of the primary flow goes through the bypass pipe, maintaining constant GPM through the chiller. You save money several ways. It takes horsepower ($) to overcome pumping friction losses as you move all that water through the hundreds or even thousands of feet of building piping. Reducing the secondary flow saves energy. Two-way valves are cheaper, less complex, and easier (cheaper) to install. The chiller always operates at design flow, where it is more efficient. So, the VF drive is needed to allow the control system to vary the secondary pump GPM to maintain constant secondary loop pressure as the load requirements change.

The strength, S, of the beam is Mc/I where M = max moment to fail = PL/4 for load concentrated in the middle of the beam or WL/8 for uniformly distributed load.

Here P is the concentrated load, W = distributed load, c = distance to outer fiber from neutral axis and I the area moment of inertia of the beam. L = length

Solving for load maximum,

P = 4IS/Lc for concentrated center load

W = 8IS/Lc for distributed load

Critical speed is the speed in RPM at which a rotating machine will destroy itself by all harmonic vibrations coinciding at maximum vibration.

Logic is an intellectual tool which has been instrumental in allowing people to figure out how to create technology. Illogical thinking does not lead to workable technologies.

A strain gauge is used to measure the strain of an object. It was invented by the inventors Edward Simmons and Arthur Ruge in 1938. There are several types of gauges (metallic, capacitance, photo-electrics and semiconductor gauges).

Yes, it does, but it is only a second order effect.

In other words, it is so small an effect that you can almost always neglect it. What is significant is the number of pulleys in use. After a certain number of pulleys there is no advantage to adding more.

The part that has a compressive force acting on it also called STRUT.

The input power, that is, the power required to operate the pump should be stated in Hp (horsepower) on the pump's nameplate. It can also be calculated by the 3-phase power equation:

P(in Hp) = VI(1.73) = Rated Voltage x Rated Current x 1.73/ %Efficiency

If this is a consumer grade pump that operates on 120Vac, then the equation becomes P = VI, simply multiply the operating voltage, 120 x current (which is the number followed by the letter "A".

The nameplate might look something like this:

___________________

| |

| Make: xxxxxx |

| Model: xxxxxx |

| Volt: xxx |

| Amp: xxx |

| %Eff: xx |

| |

|__________________|

The output power, which really isn't technically power, but rated in Gpm (gallons per minute), or capacity should also be on the nameplate. If you have the make, model, and (not necessarily needed) the serial number (also on the nameplate) you could call the manufacturer's customer service dept. As an application engineer, I have contacted countless manufacturer's service dept's for assistance. It is now big deal to them, they will be happy to answer your questions.

If it is the absorbed power of the pump to allow you to select a suitable motor then this is a function of the generated head, flowrate, specific gravity of the fluid and the pump efficency from the OEM / pump performance curve.

For those of us not in the US or using English units then the power can also be specified in kW.

In simple terms Power (kW) = Flow x Head x SG / (367 x Effy)

Where Flow is in cubic metres / hour, head is in metre, Specific Gravity (SG) being a dimensionless unit - cold clean water SG = 1 and efficency as a % from the curve or other means.

If you are trying to evalaute wire to water efficency then you can set efficency in the equation above to 1 and then ratio the input (measured power) to output power (calculated water horse power) to obtain the overall efficency.

The major function of the turbine in the turbojet is that it supplies the power to turn the compressor. An automatic fuel control unit on a turbojet engine is influenced by the burner pressure.

The easiest way to remove burnt food from the bottom and sides of a non-stick pan is to let it soak in hot water with dish detergent. A fabric softener sheet can be tossed in to soften the food even quicker. Finally, scrub the pan with a non-abrasive scrubbing pad.

pls refer to carbon-phase diagram... mild steel will be liquid and welded with temp. of >1300degC

I suspect what you're thinking of is a machine that generates more than 100% of the power it uses, which does not exist (and is in fact impossible according to the conservation of energy).