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Post by madpatty on Feb 19, 2023 19:41:16 GMT -5
Hi Andy. Impressive improvement.
Did you have to change both the compressor wheel (from the Mitsubishi TD 13 turbo you were using before) and the diffuser design as well to get to this point?
I guess you will be making another 5-10 kgs of thrust in the last 10% rpm.
Cheers.
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Post by madpatty on Feb 7, 2023 10:57:25 GMT -5
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Post by madpatty on Feb 4, 2023 23:29:02 GMT -5
Hi Racket.
Why don’t you try a brushless motor for the starter? I am using a leopard 5692 rated at max power of 5mw for my starter. I am using a hx82 rotor (98mm compressor with 112mm turbine) almost similar to your 10/98 engine and I am getting close to 18000 rpm dry during startup.
I am pretty sure there are more powerful bldc motors available out there suitable for your rotor size.
Regards Patty
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Post by madpatty on Jan 17, 2023 19:55:32 GMT -5
Hi Racket.
I totally understand what you may be feeling. Such is R&D. I’ve had my fair share of failures with my current engine.
But we have to keep going with this R&D as you always say.
Cheers Patty
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Post by madpatty on Dec 4, 2022 20:44:12 GMT -5
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Post by madpatty on Dec 4, 2022 16:26:19 GMT -5
Cannot open the video. Says it’s private Regards
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Post by madpatty on Nov 14, 2022 20:21:05 GMT -5
Hi Neo. I have used HX35 in several of my projects without issues.
It’s a good turbo with lot of spare parts very easily available.
You could even fit a HX40 turbine wheel later if you’d feel like, that also uses the same CHRA as HX35. All you would have to do is replace the turbine housing.
Cheers and All the best. Patty
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Post by madpatty on Oct 2, 2022 11:38:41 GMT -5
Hi Patty.... have messaged you, am sure we can do a deal.... i have two for sale now, as i will be using anoth pump for afterburner Just PM’d you! Thanks
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Post by madpatty on Aug 6, 2022 11:26:11 GMT -5
Hi Jetman.
That turbine is gone. Tips have melted off. Over temperature has caused this.
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Post by madpatty on Jun 24, 2022 14:30:14 GMT -5
Hi Racket. Congratulations on an impressive test run. Time to let go off the brakes and adding wings to the trailer.
Did the engine surge at 3:27 and 4:02 mark in "gauges" video or was it due to afterburner?
Cheers.
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Post by madpatty on May 15, 2022 6:37:33 GMT -5
Hi Racket. I have been analyzing the data from my engine's test runs mostly focused on the matching the turbine stage to the compressor stage. I went ahead and extracted the data from your last engine's test run when it surged and came up with this plot. Now you can see as the turbine outlet tip angle with axial increases (it becomes more closed) the static pressure at the exit increases as well and hence the throat area required at the turbine outlet decreases BUT there's a trade off, the velocity exiting the turbine also decreases so there's only SO Low you can go with the area after which the turbine exducer will start having difficulties allowing the flow to escape and that is precisely what happened in your test run (most probably). The obvious solution is to clip the turbine exducer to increase the throat area BUT it changes the tip angles and hence the velocity triangles and the static pressure at the exit. You need to have some amount of positive static pressure at the turbine exit to be able to use a converging nozzle later on. So below is the usable region (shaded in green)- More clipping will produce higher velocities at lower static pressure (lower density) at the exit and the throat area required at the turbine outlet soon shoots up pretty fast. This is what is happening in my engine's case. Too much clipping and negative static pressure at the exit. So every-time I put a nozzle on the engine, the TOTs went up pretty badly. Now of course this is based on a given mass flow and efficiency of the compressor stage and every-time you clip the turbine outlet the efficiency and flows out of the compressor are also effected (hence effecting the static pressure and densities at outlet) and you may end up in a usable region on the plot BUT this should give you an approximate direction which way you may want to proceed. You may want to clip your turbine wheel but not so much like you did in your first test run. Regards. Patty
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Post by madpatty on May 3, 2022 8:24:42 GMT -5
Calculated the turbine exducer flow area in as accurate a way as I know how....
First I carefully carved a piece of card stock that would fit between the blades:
Then I traced it on graph paper, took a photo, imported it into Rhino and scaled it to the same grid size as the paper. After that I created a surface using splines and measured the area.
The magic program tells me 0.8311 sqin/passage. There are 11 total passages yielding 9.142 sqin of flow area in the exducer!!!
Needless to say I was happy with this number Hi Monty. Did you ever measure the exhaust tip angle on these turbine wheels? Seems like there's quite a bit of factory clipping on these turbine wheels which may effect their power producing capability. The exducer throat area is also quite bigger than the similar Garrett G trim wheel. Thanks.
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Post by madpatty on Apr 23, 2022 8:14:34 GMT -5
Hi Racket. I also want to develop the mental control where everything is loaded and ready and I am just waiting on weather for the test run. How are you able to do that?
Test run it already 😂 All the best for your test run!
Cheers.
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Post by madpatty on Apr 16, 2022 5:54:26 GMT -5
In the HX82 CHRA that I have, the thrust bearing is axially supported (or axially locked)by using precision shims in a groove created between the two mating faces, the top compressor plate and the rear bearing housing, which are held together by 6 xM8 bolts. Pins are just used to restrict any rotation of the thrust bearing.
Regards Patty
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Post by madpatty on Dec 11, 2021 21:47:19 GMT -5
Hi Racket.
Yes there are 2 pins inboard of the curvic. I think that shaft will come out eventually.
I also think the exhaust and the coupling are a single piece. I don’t know if I can machine it.
I still don’t know how these are joint?
Thanks
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