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It's true that conventional turbines perform a lot worse at small scales. Here's some commentary from Prof. Warren Rice (Arizona State University) on the topic: https://www.gyroscope.com/images/teslaturbine/TeslaTurboMachinery.pdf Of note, he states that tesla turbine rotor efficiency can...

It's more than just the output rpms being too high. Practical tesla turbines usually have isentropic efficiency of about 30%. A large multi-stage reaction turbine can exceed 90% isentropic efficiency, so between the two it is no contest. Then you have the problem that no practical turbine...

Attached is my new and improved steam turbine spreadsheet, now compatible (well, actually only compatible) with superheating. The sheet is prefilled with a solution for a 3 stage Rataux turbine that is matched to Steamchick's boiler, should he fit it with a superheater. Worth messing around with...

They aren't used as turbines but do find some applications as pumps, for situations when tolerating entrained solids or minimising shear forces on the fluid are more important than efficiency. I've been enjoying this thread mostly because it prompted me to start learning the thermodynamics of...

My plunger passes through the middle of a control collar that has a slot cut in it. The plunger is cross drilled for a pin that rides in the slot.

My spreadsheet assumes that the steam doesn't condense, it just expands isentropically through the nozzle, staying at the saturation point. Kind of an idealised scenario, but not far off the mark practically because turbines usually cannot tolerate too much condensation without damage. It also...

Apparently full sized turbines have drains, so I'd just add one. I think you would ideally have enough superheat that the steam does not condense significantly within the turbine, once it is up to temperature. Apparently impact damage from water droplets hitting the blades is a significant...

My spreadsheet says that for your design parameters (pressure, rotor diameter, etc) and pure impulse operation your optimal speed will be about 70,000 rpm. Also in the absence of a condenser or feed water preheating your 3 kW burner should be able to provide enough steam for about 25W at the...

I'm making some progress on the injection pump. The body of the pump and the barrel are done and the barrel has been lapped, though I may give it one more go with finer abrasive. I also made a plunger. Both plunger and barrel are of silver steel and hardened by quenching in oil. Worked well for...

I think the reason is that practical Tesla turbines usually have rather poor performance compared to bladed turbines, so they are just not often used. As I understand it Tesla turbines have received a bit more development as pumps, they have certain advantages when handling fluids with...

It would be more accurate to say that (almost) the whole enthalpy drop happens in the nozzles. Other pressure drops from 'non ideal' characteristics of the machine represent a rise in entropy, which doesn't do work. A nice side effect in pressure compounded turbines is that some of the losses...

I just had the thought that the volume of the steam pipes going to your turbine might be big enough to give you some cushioning from the steam itself acting as a spring.

Engine mufflers are complicated. They work at least partly by creating destructive interference in the sound waves, which is why they often have multiple different sized chambers inside, to affect different frequencies. How bad is it to have pulsations in the boiler feed? Would think that the...

Needs some way of joining all the pieces together solidly while you make the mould. Could have a shoulder on the middle piece and matching steps on the outers, so you can use countersunk screws?

Ahhh I see, they have different helix angles to create the ratio. I thought you were doing normal screw gears, which can be had as stock items: https://khkgears.net/new/screw_gears.hml

If you just need one pair of gears you could possibly have them 3d printed in metal. Lots of commercial services doing that these days. The other thing to consider is whether some stock gears will suit your application. I did get quotes on some a while ago, and they were expensive but perhaps...

Will you use atmospheric intake valves again? If going SOHC you might consider placing the valves in a row along the length of the engine so that both inlet and exhaust can be worked by the camshaft. Inline 6s have a distinctive sound, always reminds me of my grandparents' Ford Falcon from back...

I would assume the potential pressure ratio of a tesla compressor is similar to that of a normal centrifugal one. So practically speaking perhaps 3:1 or 4:1 per stage. What will be interesting is to see if it has a surge line like a bladed centrifugal compressor.

Looks good!

Indeed it is viscous drag. Take note of the differences between turbulent and laminar boundary layers too, they will have an impact on the turbine's behaviour. However this doesn't explain how it can be operating as a reaction turbine. One potential hypothesis that comes to mind is that the...