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As far as consumer products go, it's a very recession-resistant business, which is remarkable being at how much pricing power Apple has on its products. It's a sticky ecosystem, and if you have one product, they got you in their ecosystem and you're just going to keep going. I'm still going to get my wife the newest Apple Watch for Christmas.
#HOLD UP IN PIPESIM UPGRADE#
I'm still going to upgrade my phone when my children inevitably break my screen. If we see a 2008, 2009 recession, my Apple Music bill is still going to be paid every month. That's a sticky source of revenue and it's a recurring source of revenue no matter what the economy is doing.
#HOLD UP IN PIPESIM MAC#
Just to give you the rest of the breakdown, 11% came from Mac sales, 10% from iPads, 11% from wearables and accessories, and 22% of its revenue came from services.Īpple, I like because it's a very sticky ecosystem that people will continue to participate in no matter what, especially that services business, which is not only the second largest single-source of revenue in there, but it's growing rapidly. It made about 47% of its revenue from iPhone sales in the most recent quarter.
#HOLD UP IN PIPESIM DRIVER#
Apple, its biggest revenue driver is iPhones. It trades for, I think over eight times sales, which for a consumer products company of that size is lot. I get the fears - that Apple is a big, highly valued company. Some research papers have been published on this recently but I don't exactly know in which journals.Matt Frankel: We all know Apple. Hence, riser diameter does influence the flow pattern and hence liquid hold-up prediction. However, with larger diameter, it was observed that for the flow pattern changed from bubbly to churn and directly to annular, yes, no slug flow.
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These flow pattern maps were developed based on observations and experiments in smaller pipe diameters. As the gas fraction increases, most flow pattern maps would predict transition from bubbly to churn and subsequently to slug flow before changing to annular flow. One of which was on the transition of flow pattern in risers with large diameter. Some research on two-phase flow have been extensively carried out at Univ. And I can stress that his last two points on pipe diameter and the difference between air-water mixture with real hydrocarbon two-phase mixture are the main reasons that causes the Beggs and Brills to fail at predicting the liquid hold-up in large riser correctly. I was about to shed some lights on this odd hold-up profile but I guess Steve had aptly summarised the points leading to these anomalies in the post above. Can you explain what you mean when you refer to the "various" friction factors? I've let PipeSim calculate the frictional losses based on the roughness of the material, and I believe that's all I could do. It is a (fairly light) hydrocarbon gas-condensate system. When you make a move to things like the Shell, Olga or other mechanistic correlations, you see this behaviour at very low flows and low condensate-gas ratios (eg when there is little condensate). it's based on air/water systems, not something as nearly phase-continuous as gas/condensate/aqueous systems. it's optimised for the normal part of the flow regime. That's right - Beggs and Brill doesn't predict this behaviour - but that's for a few good reasons I am not sure how this can help u but plzz do check this out can i ask u something what type of fluid are u talking about and did u take the various friction factors into considerations Interesting - so Beggs&Brill apparently doesn't properly predict the flow regime / slugging in the riser? Three out of four correlations suggest the second curve is right, but I'm a little cautious about going with the "unusual" behaviour.Ĭan anyone here shed any light on this odd behaviour? Nearest I can figure out, I've somehow exceeded the validity range of the mechanistic correlations, or else there's a mechanism other than deposition and entrainment going on which kills off the holdup at low flowrates. The odd thing is that using three standard mechanistic correlations (Olga, Shell and Ainsley), I'm getting the second curve, but if I use the default Pipesim correlation (Beggs and Brill revised), I get the first curve. In the problematic case (which is a gas-condensate case with little liquid and low gas flowrates), I'm seeing the second sort of curve, which is low at the start, high in the middle, and low at the end.
![hold up in pipesim hold up in pipesim](https://www.notrecinema.com/images/filmsi/hold-up-a-l-italienne_629595_13389.jpg)
![hold up in pipesim hold up in pipesim](https://docplayer.net/docs-images/111/197517388/images/14-1.jpg)
In general, I'd expect my curves to look like the first one in this uploaded file - large holdup at low flowrates, and low holdup at low flowrates, following an asymptotic-like decay. I've been doing some pipeline modelling in PipeSim recently, and I've found a really puzzling holdup-vs-flow curve, which runs counter to every other holdup-vs-flow curve I've seen before.