Metallurgist here, I am currently looking for good book on design of turbomachinery components.I am currently designing a building a piece of equipment that will rotate a 1 foot diameter component up to 50,000 RPM (picrelated). I'll be operating this thing inside a stone bunker I am currently constructing to avoid landing on the list of inventors killed by their own invention, but I'd like to do some engineering to verify the disc rupturing won't ruin the past year's worth of work. I understand the basic concept is you integrate the burst pressure equation for a disc (s=(v^2)*(D^2)*(p)/3) over your component. I plan to make a Matlab script that will do this from my CAD part. But I'd like to have a textbook with worked examples so I can verify my script gives the correct answers. Back of the envelope calculations gave me a burst pressure of about 20ksi for an aluminum disc, so if I use 7075 I should have a nice safety margin there as long as I properly design my joints. Naturally the first thing I do with these life-or-death engineering decisions is come to 4chan. But if anyone has some good recommendations before I start just shotgunning used books I'd be very grateful.
>>16854298Its either a centrifuge or energy storagethe centrifugues have two bearings, one is a needle bearing and the other is magnetic. I feel like you could do instead with an air film particularly the needed bearing using a hydrodynamic thrust bearing, a lot has been written about it. I dont know if the air would interfere with the gas separation .They are made of marangian steel which is allegedly able to be stretched a lot forming thin cans and has high tensile strength (compared to what?)
>>16855111I'm building a custom centrifugal blasting unit. It's a very non-standard application.As for material choice, I went with AA7075 on the basis of: 1. Operating at room temperature.2. Relatively low cost with pretty good strength to weight ratio.3. Machining hardened steel / titanium / nickel superalloy would be excruciatingly difficult. Long term I'd rather avoid aluminum given the lack of an fatigue limit as at these rotational speeds HCF will be a serious problem long term. That said, I just need to get proof of concept with the first few tests.
>>16855358How are you going to spin and balance it?I had good luck in projects by starting with shitty versions that i would just improve.
>>16854298not much info to help, but I am very curious- are you using this to make a machine to grind feedstock down form sand grain to nanoscale via attrition, like an air grinder, but what appears to be an impeller driven by a series of air pistons, likely plc controlled from a solenoid valve bank, making a cheap quick and easy power supply and not having to use an expensive vfd and 3 phase motor because of the low rpm torque falloff and vast range of rpm and minimum torque requirements?am I close? very curious, I am doing something similar.
Bump, gl
Bro what is there to learn, turbomachinery can be so many things.You need hydrodynamic or hydrostatic lubrication and very good balance and materials that can take the centrifugal forces.I simply suggest you start at lower RPM and if it works, increase them until you find a hard limit.https://youtu.be/lOTWx69mghM=uKRw7_Prs3J08BmiLink to commercial air bearings, the same thing can be done with oil with looser tolerances
>>16858125I've already filed a patent application so may as well spill the guts. But first, two existing technologies:In cold spray you use heated pressurized gas to accelerate (usually metallic) powder to supersonic speeds to deposit a coating. Impact velocities 300 m/s - 1100 m/s. Wheelblasting (aka wheelabrator) uses an impeller to fling shot at a surface. Either to clean the surface or to shot peen the surface. Maximum impact velocities typically 120 m/s. To get the impact velocities I wanted I calculated I need about 50,000 RPM for the wheel. So I'm trying to build a turbocharged wheel blaster that flings powder at sufficient speed to achieve metallurgical bonding on impact by mechanism same as cold spray. I've been working in cold spray for about 10 years now. Certainly drawbacks compared to conventional cold spray, but also possible use cases with great promise. As for the pistons - those are simply keeping the top/third roller of the steady rest in contact with the rotating axle. The system is designed to just run at one speed, no variable speed control of any sort. For now I just want to show proof of concept, then worry about optimizing parameters later.
>>16858609super cool. I figured you had some sort of reverse driven worm drive to get high rpms. you might have some luck just buying an off the shelf centrifugal lube oil purifier, especially the ones with conical seperation plates. you could probably just keep the spindle and machine base, adding your slinger on top and be done. those spin at around 15k rpm, and if you need to get higher speeds, you can probably just boost oil pressure a bit, change a few belts, and maybe watch for thermal stresses.my little project similar to yours is wet grinding materials using a conical diamond bit as the rotor with a hardened steel surface as the stator. right now I am using a vandaium socket, conical diamond bit, some stainless kegs off craigslist, and an er-30 collet extender for a cnc machine as the spindle. I need to setup a mechanical seal for the shaft to hold vacuum and a slight positive pressure.the first thing I want to do is ferrosilicates, some hydrocarbons, and some cupronickel alloys. the interesting part you might like, and some of the metallizing coat processes I want to do at the end, is to have the wet slurry come out, dry out, and easily be at the nanoscale. this means easy nanoconcrete slurry with wacky ingredients, but also it means using the cavitation plume from the rotor/stator gap with a microwave radiation booster to extend the adiabatic process more towards the plasma range. I also want to toss in an ultrasonic transducer. I think I can force specific molecular bonds to form, like when brewing up hydrocarbons, and in this case, making different alloys for vacuum casting, metallizing sprays, and electroforming fluid.that is sort of the endpoint- a wet nanogrinder to make slurries, powders, etc... mostly for electroform prototyping, especially making exotic alloy solutions to electroplate mold forms like they used to do with turbine blades and housings. no need for hot forming, edm, or a cnc machine.
>>16858609>I've already filed a patent application so may as well spill the guts.Bro this doesnt work good luck suing some jewish coporation at the court of jewstice when they steal it, best defense is obscurity or just making a design very public so unpatentable
>>16854298w...what do you use the pressure cookers for?
>>16854298If you must develop new formulas because they don't exist in literature, of course use the pi-Buckingham theorem.
>>16858604I don't want to find out what the maximum force my impeller can take is at 50,000 RPM though ha. Rough calcs show I should be good with a high strength aluminum, but want to verify with FEA. >>16858611I use a timing belt to step up from 3600RPM to about 10,000 RPM. To get up to 50,000 RPM, the lower steady rollers have a diameter 5x the diameter of the shaft holding the impeller (steady rest rollers are driven). I did a similar design working at a company 5 years ago where I made a small scale centrifugal plasma atomization unit for making metal powder. There's a company called MPW (Metal Powder Works) doing something sort of similar to what you are trying. It's basically just a CNC lathe using an ultrasonic transducer typically used for welding. Typically results in powders 10-100 microns and only works for metals that are machinable, operating somewhere around 1000RPM. Their machine is very limited and their powders are total crap but for some reason they are now valued at $200 million. So if you can produce powders by grinding without having to change tips every other minute that'd be pretty cool. The big problem with these rotating machines and metal powders is the nightmare that is going to be for bearing life ha.>>16858809I am aware a patent isn't invincible armor and didn't waste money on a lawyer, I did all the legal work myself. The fees for micro-entity filers are pretty low. If this technology is successful enough for someone to want to steal it, I'll already be pretty ecstatic. Now the odds are if one company wants to infringe, another company will want to as well. And in that case the plan would be sell the right to one so they can then screw over the other. >>16858879I use the small one for melting wax for investment casting (picrelated), bigger one for distilling. I need fewer hobbies. I promise mister Fedman the only weapon I've made (not counting knives/swords) is a semi-automatic crossbow.
>>16859066>metal powders is the nightmare that is going to be for bearing lifewet grind. the easy part is the conical rotor and the hardened stator. I will use stellite later. modification of the cavitation plume with a microwave beam and some ultrasound is probably overdoing it, but the ones I have seen with some success have been using that cubic boron nitiride stuff. either way, the next is figuring out how to keep the diamond grit on there, since I will be using stuff like bearings or wire cuts of titanium as feedstock and need them to get the big grind done with that before cavitation and destruction to near molecular level. next avenue to explore is making cupronickel alloy with some cbn or diamond grit mixed in. the next thing is to work out a cyclone seperator with size classification to recirculate water back into the grind cavity, since as you mentioned, my 10krpm spindle is going to have some problems.my solution so far is to have the clean water recirc lines flush the mechanical shaft seal immediately in the pressure vessel, and having the cyclone unit makeup the difference with the overflow/buffer tank. that and I will probably make a silpat gasket as a final barrier with clean water flushing that annulus.my reason, there is a big push now in aerospace for using 55 gallon drums full of colloidal metals for electroform prototyping, essentially long term electroplating. can do exotic alloys, layers, ac/dc deposition, spot deposition, etc... liquid electric spray paint for metal. beats the approach of using vapor deposition or sputtering on a cold carbide form. think of amoporphous metals and stuff like that. no need for high temperature and ultra rapid quench, just build up electrically in solution and refill from a drum.interesting field. looks like you are having fun.
