aviatoreb Posted April 7, 2018 Report Posted April 7, 2018 52 minutes ago, carusoam said: The flow mathematics/calculus must get pretty interesting as the Airspeed increases... the fluid pumps have to pump against the head pressure of air trying to push on the leading edge... the speed of the air rushing by, affects the flow and distribution of the fluid that is being delivered... real speed of air particles whizzing by, vs TAS that includes a pseudo calculation for air density.... does some % evaporation occur in real time use of the product? As a student of fluid flow in pipes... the air in the pipe mostly got ignored as a force. It’s viscosity is near nil. It’s speed is usually zero... On the wing, the flow isn’t even linear, plus it is 3D, the pressure is actually a vacuum, it’s amazing that the fluid stays so well adhered to the surface under those conditions... Benoulies were brilliant! Best regards, -a- ...but how thick is the boundary layer at the leading edge and how thick is the fluid layer at the leading edge? Could it be that the fluid is pushing itself mostly into still air if it is a fluid layer that is thinner than the boundary layer? I know the boundary layer at the leading edge will be pretty thin but... 1 Quote
carusoam Posted April 7, 2018 Report Posted April 7, 2018 Dynamic still air...? Would we consider the fluid or the individual molecules... the individual collisions are paint peelingly interesting...? I would expect that we can view the air as a fluid, that has no motion on the leading edge, but still has a pretty high average pressure applied over the CSA of the wing... The split line, where the air splits and goes over the wing must be below the TKS pores... all the TKS fluid goes over the wing? Or does the TKS fluid have a preference for splitting as well? aaaahhhh... back to the topic of boundary layer thickness.... We expect the boundary layer to be as thick as the VGs are tall... in that location.... not sure how to measure or view it’s thickness at the leading edge. When flying in the rain.. do you see any flow patterns caused by the VGs...? Does the water meander by, or go by so fast you can’t see it? Meandering would be an indication of a really slow boundary layer I know the speed brakes generate some interesting flow characteristics that really are noticeable when deployed in rain... (MS video) For an interesting flow study... consider putting a food coloring in with the TKS fluid... be sure it is not compatible with the new paint surface first! Wouldn’t want a dye to stick to the new paint... Studying flow of non-ideal, compressible fluids in 3D has never been more interesting...! One of the fluids turns into a solid in the middle of the study... the solid changes the shape of the surface that the air is flowing over... Spooky stuff if you are riding along in the experiment... PP thoughts only. Erik introduced me to a colleague. The colleague taught transport phenomena to a gent who became a professor... that professor in turn, taught some low level transport phenomena to me... small world... Speaking of Small world... I believe it’s the name of the coffee place Erik and I sat and discussed AOAis with a particular young math student... Best regards, -a- Quote
aviatoreb Posted April 7, 2018 Report Posted April 7, 2018 49 minutes ago, carusoam said: Speaking of Small world... I believe it’s the name of the coffee place Erik and I sat and discussed AOAis with a particular young math student... Actually that particular young math student is at Cornell - but he is mostly an MAE student specializing in fluid mechanics. And doing fantastically well! There is a fault with what I said....the fluid could be stationary but still under increased pressure so it could be that the pump has to work harder. I don't know...I am trying to logic my way into this thing and it would be very easy for me to make a rookie mistake. This isn't specifically my area - meaning I know just enough to make me very dangerous! That can be sometimes worse than knowing nothing. 1 Quote
Piloto Posted April 7, 2018 Report Posted April 7, 2018 The impact pressure on the wing TKS surface is greater than the static pressure on the TKS tank as altitude increases. Because of the pump limited capacity this causes a flow reduction. A bigger pump would solve the problem but risk bursting the lines. Similar problem happens with vacuum systems at altitude and why the use of electric gyros on the flight levels. José 4 Quote
exM20K Posted April 7, 2018 Report Posted April 7, 2018 The impact pressure on the wing TKS surface is greater than the static pressure on the TKS tank as altitude increases. Because of the pump limited capacity this causes a flow reduction. A bigger pump would solve the problem but risk bursting the lines. Similar problem happens with vacuum systems at altitude and why the use of electric gyros on the flight levels. José Ah! That makes sense. I never considered he static pressure. And thanks, guys for JW fluid dynamics ideas. Quote
CAV Ice Protection Posted April 8, 2018 Report Posted April 8, 2018 On 4/6/2018 at 3:20 PM, exM20K said: Joel, Thread hijack.... Can you tell me the reason for the high-altitude airspeed restrictions for FIKI M20TN's? -dan Hi Dan, I have forwarded your question to our Design Engineering VP who was instrumental in the Mooney M20 FIKI certification program. On Monday I will be traveling and have limited email access. CAV Ice Protection is attending MRO Americas in Orlando to promote our Part 145 repair station...and a summer sale that affects all TKS owners and operators. I am pumped to share it with you. Stay tuned for both on Monday, and have a great rest of the weekend! Best regards, Joel 1 Quote
thinwing Posted April 8, 2018 Report Posted April 8, 2018 On 4/6/2018 at 6:23 PM, exM20K said: 173 KIAS at 11,000. -3 KIAS every thousand on up. Maybe he picture will load from iPhone. If not will upload later Interesting I do not recall seeing a speed restriction as shown for my Bravo.. Quote
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