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About Geoff_H

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  1. Oct 15, 2018 New #48 "Geoff_H, were you referring to the Navier-Stokes equations? They have been around for years longer than you said. And incomprehensible to us poor mortals." The way I understand it the first solution of the Napier stoke equations for ships hulls was done in 1896. I think that it was a mathematical solution to the differential equations. I think, but not sure, that it was using a froude number maybe in three dimensions
  2. The most interesting story that I was told about aviation mathematics was told in 1970 when I was at Uni. Early in the 20th Century (around 1915) aeronautical were working on the mathematics of fluid flow around a solid body, they were so proud of themselves determining all the mathematics using first principles and then published their research only to be informed by naval architects that they had developed the mathematics 20 years before. L ack of communications!
  3. For my money both are exactly the same. An object produces a force equal to the mass change in momentum that it causes to the air, or fluid if we are talking about boat props. But try and work out the lift using the change in flow. To theoretically work out lift use the Dell operator around the wing. Very complex mathematics. However Bernoulli's theorem with a lot of factors to make a single instance of the equation work and you have the most appropriate equations work. There is a website that offers a two dimensional solution using the Dell operator mathematics. But even that is approximate, the three dimensions makes it much more difficult. I did three years of university mathematics and four years of engineering nearly 50 years ago and so the Dell operator is just a faint memory. 20 years ago I got the old books out. I was totally lost in how to do the mathematics. I just use the Bernoulli's equations with correction factors determined by wind tunnel testing.
  4. Geoff_H

    Upturn in GA Learning to fly

    I wish that I had never made the throwaway comment about the possible lack of need lot pilots in the future. I was seriously trying to find out if there was a genuine upturn in people wanting a ppl. A friend of mine was asked to buy an aircraft and put it on line to make money. Basis of the request was that he could expect 400 hours per year of hiring. Any comments
  5. Geoff_H

    Upturn in GA Learning to fly

    I worked in super reliable control systems. The first 4 Airbus crashes were a result pilots overriding the control systems. Now Airbus have many actions that are cannot override. Accidents in Airbus aircraft are very rare. When we design superstars control systems we look at the reliability of each individual "control system" usually ifr something is too hot we measure with 2 to 4 temperature devices and use 1 to 4 devices to regulate the temperature. A solenoid may have been tested and failed 1 in every 10,000 operations. We multiply all systems out to get a probability of failure that the systems cannot control . For human travel these systems have to be greater than 1 in a million hours. Why is this relavent? When the control device is a human, the probability is 1 in 2! With excellent training, like I am sure that you provide, it is much better, but no where near the safety figure offered by multiple redundant control systems. I have now retired but 45 years in the control industry have seen me not wanting people's jobs taken by control systems. I don't think that we as humans are going to cope with a lack of purpose . Unfortunately the economics of peopleless machines will win out when big business are just after profits. Who would ever the banks would be like they are today because of automation.
  6. Geoff_H

    Upturn in GA Learning to fly

    I expect bus drivers employment will be o lot less than 20 years. Bus and truck drivers are the source of money making driverless cars. Airline pilots are only there to make frightened passengers feel safe lol
  7. I have had a report that there has been a large upturn in the demand for GA pilots licence. Has anyone else heard this? I suppose as the airlines are having a demand. Personally I expect pilotless aircraft in around 20 years I wonder if an airlines job has so much future.
  8. Geoff_H

    Fees to fly

    Point taken. I don't know what other words to use
  9. Geoff_H

    Fees to fly

    I could not agree more. The expense that made the cost around double was that my doctor was not equipped to test my eyes. She asked me to go to an optometrist. The optometrist charged $160 for an eye examination for a heavy vehicle licence. I have a licence that the medical does not all ifr flying, no endorsement so no worries . No night flying, well I think that my night vision is not as good when one gets older, so not really an issue. Biggie is aerobatic flying. Something I was about to start, but next year I can do a dame exam and then get all privileges back.
  10. Geoff_H

    Fees to fly

    Sorry, just read profile. I see that you are in Great Britain. Age is getting to me lol
  11. Geoff_H

    Fees to fly

    Where are you located?
  12. Geoff_H

    Fees to fly

    Sure, but using your driver's licence foris a lot less expensive. But your point is well worth your mentioning it. Appreciate your effort.
  13. Geoff_H

    Fees to fly

    My basic Class 2 medical just cost me $330. Now that I am 70, this could be each year! None get away cheap.
  14. Geoff_H

    Temora and Narromine airpark.

    Found a publication that says floor height for house must be 500mm +1% flood level ( no idea what it means) above ground. Looks like it floods, hangar may have lots of water in ir
  15. Geoff_H

    Sling 4

    I expect with me in it .