I am looking for companies who provide generator cleaning services. The lower end turns on one of our pumped-storage units were contaminated by turbine oil mist when our mist extraction fan failed several years back. The oil has since collected brake dust, metals, and some asbestos fibers. We...
Hydro units of this vintage are generally controlled by a mechanical governor. In our plants the maximum wicket gate speed is ultimately limited by the hydraulic oil flow rate through the main spool valve. But if a hydraulic line between the servos and the governor were to fail then gate...
I would like to relocate our residential 3-ton A/C condensor so I can build a patio. I'm planning on running the line set underground in a 4" PVC chase. The underground run will be 15' to 20' long and sloped back towards the evaporator. I'm debating on if I should have the contractor install...
I wonder if you can do something equivelant to autorotate or glide in this thing. I for one would like to have some means of safely landing an aircraft if the engine(s) crap out.
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
Hmm...a 5 mil interference fit would be a loose fit between the thrust collar and shaft on one of our hydro units. That leads me to suspect the scale of ginsoakedboy's thrust bearing is a bit smaller than what I'm used to working with.
GSB, can you provide any information on the dimensions of...
Remember, the winglets are set at an angle to the wing. It's lift vector is more horizontal. You can have a winglet with an angle of attack that will generate a force outward which will counter the vortex generated by the circulation around the wing. An outward force generated above the wing...
Actually winglets serve many purposes, it extends the effective span of the wing without impacting the physical span of the wing. This means you don't have cut notches in your hanger doors when you buy the extended range 737.
They can be pitched slightly outward to reduce both bending moment...
Your right btrueblood. They probably design multiple winglets so the customer can select the optimum for their flight profiles. I do recall on glider pilot at Harris Hill that had three wing tips, one straight and two winglets. He said something about selecting the tip based on forecast...
Everything I said above was tongue-in-cheek.
The best way to reduce drag on a vehicle is to reduce your speed. Aerodynamic drag is a function of velocity squared. Reduce your speed from 75mph to 65mph you will reduce aerodynamic drag by about 25%. Jimmy Carter was pretty darn smart when he...
The winglet angle of attack is a function of the wing tip vorticies. Change the loading on the wing and you change the circulation around the tip of the wing which will change the angle of attack on the winglet.
I haven't heard of adding winglets to improve climb rates. This is usually such a...
How to dimple your car for aerodynamic efficiency:
1) first spray the surface of your car with blackened oil. This will work better if you have a white car.
2) drive down the highway
3) note the transition area from laminar to turbulent by the change in oil film
4) locate a line about 5-10% of...
Winglets are designed to be effective for a very narrow range of angles of attack, usually to optimize cruise. Since your angle of attack will be higher for glide and turn you will probably find winglets are detrimental to performance.
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
Thank you all for your responses. This is a very interesting discussion.
We will be rewinding this unit. It is currently scheduled three to four years out. We have decided not to risk damaging our fragile winding at this time by moving the stator.
In the mean time I will be monitoring...
We can move the stator. It's just there's a camp of experts telling me not to move it. This is a 30 year old winding on a pump-generator. It's past it's prime and a recent PD test is showing weakness. I'm trying to learn all I can about the implications of not moving the stator.
Regards...
