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Post by madpatty on Dec 11, 2021 20:04:54 GMT -5
Hi Racket. I am not able to see any alignment locators between the two split pieces of the impeller. The rear internal spline seems integral part of the turbine wheel whereas there is a shaft press fitted on the exhaust side of the impeller. I still cannot find if that big chunk of metal with curvic coupling on the exhaust side is integral part of the turbine or no. Some more pictures for your reference. I am not sure how these split impellers are assembled. Thanks
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Post by madpatty on Dec 11, 2021 18:25:20 GMT -5
Hi Patty Why do you need to disassemble the unit ?? Cheers John Hi Racket. Because all that extra weight on the exhaust side of the turbine is of no use and is a huge cantilever load for any turbine side bearing. Also it would be harder for me to make external spline and also install a rear bearing at that location. It would be best if I could make my own shaft and just use a usual two bearing design we all use here. Thanks
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Post by madpatty on Dec 11, 2021 7:42:39 GMT -5
Hello All. Been thinking about how to use this turbine. The turbine is made of two separate sections (joined together I don't know how)as you can see in the pictures. The long shaft is a press fit "through" the turbine and I think it can be removed out probably by using a hydraulic press or something. If anyone knows more details about how these impellers are assembled or disassembled then please share. Thanks.
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Post by madpatty on Nov 25, 2021 6:16:35 GMT -5
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Post by madpatty on Nov 25, 2021 6:09:08 GMT -5
Hi All. I have been contemplating the basic design and how each component will be joined. Which kind of bearings to use(brass or balls) and bearings placement. The turbine has this extra long extension on the exhaust side which will cause too much of an overhang if I’ll use bearings between the compressor and turbine. The turbine has a through bore with a shaft extension press fitted through(maybe acting as tie shaft or bearings support in the apu). Any ideas are welcome. Thanks
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Post by madpatty on Nov 25, 2021 6:03:29 GMT -5
Hi Patty, This runner belongs to which engine? Cheers Ralph Hi Ralph. Not completely sure. Only know that the Turbine belongs to GTCP-100 apu. Regards
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Post by madpatty on Nov 24, 2021 14:16:46 GMT -5
Hi Guys. You read it right. I thought, in order to keep myself motivated, I should start a build thread of this Overly ambitious but not impossible project. I have acquired this titanium compressor impeller (170/230mm). My preliminary calculations show, this impeller is good for ~400lb thrust at modest 3.5PR. But finding a suitable turbine is a challenge. I need something in the ballpark of a 215mm axial turbine or a (215/170mm radial turbine) The turbine that I have is slightly too big at 270/185mm. If any of you have any suggestions and comments please let me know. But sure this pair looks too good together. Cheers.
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Post by madpatty on Oct 21, 2021 21:21:15 GMT -5
Good Luck Racket. 👍
Cheers
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Post by madpatty on Sept 26, 2021 19:26:38 GMT -5
Hi Joe Yep , you need pitot tube total pressure gauges before each turbo turbine stage, as well as thermocouples . Speed of sound is temp related , the hotter the faster, ~2,000 ft/sec isn't unusual in a glowing turbo , pressure isn't important . As for the flow through the HP turb , I checked out the turb map www.garrettmotion.com/wp-content/uploads/2018/05/Turbine-Flow-GT47.jpg for the Gt47with a 1.39 housing and it gave 55 lbs Corrected , so added on a couple more for your bigger housing, I used 800 Deg C - 1073 K as the TIT Now Corrected Flow = Actual Flow X sq root of TIT/288 all divided by the PR going in Corrected Flow = 165 X sq root 1073/288 divided by 5 = 165 X 1.93 divided by 5 =63 Now 63lbs/min Corrected Flow is considerably bigger than the 57 lbs/min on the map , so to get 57 lbs/min Corrected I needed to increase the PR going in , basicaly increase the density . 165 X 1.93 /5.6 = 56.8 ..............Corrected now equals the map. Hope this helps Cheers John Hi John. Turbine maps have always been confusing. I always thought the mass flow on the y-axis of the turbine map is the maximum the turbine can flow and as we can see the flow sorta becomes constant once after a Certain PR value so no matter however much you increase the PR going into the turbine you cannot increase the mass flow going through it. Is it true? Is the PR on the x-axis of the turbine the PR going into the turbine or the PR across the turbine? Or is it just that turbine maps show what maximum PR across the turbine, a given turbine can process(sorta like what maximum work a turbine can perform) Thanks
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Post by madpatty on Aug 31, 2021 19:59:18 GMT -5
Hi Monty. I was just wondering how’s the rotor dynamics gonna look like for this modified rotor especially with an overhung gear and single brass bearing between the compressor and turbine.
What are your thoughts on that?
Regards Patty
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Post by madpatty on Aug 31, 2021 19:19:01 GMT -5
Shoutout to the fun days when the world was still free of the 🦠
cheers. Patty
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Post by madpatty on Aug 30, 2021 5:14:02 GMT -5
Hi Mark, Nice work on the trike! I am looking forward to hearing it roar for the first time. In hindsight it wasnt the best idea to delete the YT account, but I was pissed off one night when another one of my favourite channels got deleted for speaking against the government narrative. I am uploading the old videos at: www.youtube.com/user/MobackenracingCheers! /Anders Hi Anders. See, I told ya. We have been missing you a lot😀 Good to see you back mate. Thanks
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Post by madpatty on Aug 27, 2021 7:15:26 GMT -5
Hi Patty Yep , creep has occured , as would happen from an "overspeed" increasing tensile loads beyond the strength of the material , any gyrations will impose additional loads to those just from rotation , this combined with any abberant heating or vibration will surely stress even the best material . Just throw the wheel away and get a new one , thats what I did with my FM-1 engines wheels after each failure . Cheers John Patty the next day 😁 😂😂😂 This is an expensive hobby for sure. Cheers
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Post by madpatty on Aug 26, 2021 9:46:06 GMT -5
Hi Racket and Chris. Its just a scrapped off line from my pocket screwdriver in the first picture. The crack is just a pinhole. Well it’s an aftermarket turbine wheel not an original Holset one. racket. Creep has happened otherwise how do you explain the dimensional increase of 2mm Chris I don’t understand what you mean by “The hole does appear to be inline with the rub radius and as such, maybe it was at the line of flexure and this took a sufficient alternating stress.” I have used turbine wheel from the same supplier before and have never experienced anything like this. Thanks
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Post by madpatty on Aug 25, 2021 21:07:01 GMT -5
Hi Patty If there was a bearing failure the resulting gyrations will result in extra tensile loads being placed on the blades above the usual ones from temps and rpm , it might have exacerbated an already "weak spot" in the wheel . I've had a wheel "expand" during a bearing failure and had to cut the tips off the wheel with the oxy torch so as to disassemble the engine Cheers John Hi Racket. There wasn’t any bearing failure at all. Engine was started and shutdown a couple of times. Total time on this turbine wheel is about 30 minutes. Thanks
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