Sailing Theory Tutorials - Sail Trim, Separation, and Stall

This video introduces the concepts of angle of attack, flow attachment and separation, and the stall condition.
Trimming the sail in is related to increasing the angle of attack, and it is mentioned how angle of attack can affect the lift and drag forces generated by the sail.
Trailing edge separation and stall are treated with reference to the leech telltale, and laminar separation bubbles are discussed with reference to their effect on the luff ticklers.

Пікірлер: 27

  • @howarthsailing
    @howarthsailing3 жыл бұрын

    Hi Everyone, I made some changes to my channel this winter that resulted in YT deleting all of my comments/replies on these videos. It's really a shame, because I feel like I have answered quite a few theory questions in the comments section over the years. If you have a question, even if it looks like it's been asked before, please don't hesitate to post a comment, I'll do my best to get back to you. Cheers, JH

  • @stevekirby4874

    @stevekirby4874

    Жыл бұрын

    Many thanks for your videos Julian. I’m learning so much 😊⛵️

  • @algotrader8677
    @algotrader8677 Жыл бұрын

    Excellent ! Love the combination of theory and practice explained visually in simple terms.

  • @jamesa1116
    @jamesa11163 жыл бұрын

    Superb, simply superb. Erudite, deals with the subject matter very efficiently, clear presentation with concepts building on one another and a summary. Doesn’t it make you heart sing when you find someone who is such a class act at their chosen task?

  • @benmonette7593
    @benmonette75933 жыл бұрын

    Just discovered your lessons, thank you for making all this public and making it so clear.

  • @DavidHarbinson
    @DavidHarbinson Жыл бұрын

    Julian, I have just discovered your tutorials on Utube. I am reasonably new to sailing so on a big learning curve. Your video on Sail Trimming Separation and stall is excellent. Really starting to understand what is happening with tell tales, why and what corrective action you need to take. Really appreciated thanks so much.

  • @yachticus
    @yachticus5 жыл бұрын

    Julian - well done - excellent delivery - and a good concise explanation

  • @freddyrassinger8198
    @freddyrassinger81986 жыл бұрын

    Thanks Julian. Beautifully illustrated. Well paced and the length was perfect 🇬🇧

  • @backwaters3660
    @backwaters36605 жыл бұрын

    Well explained, thank you!

  • @g.gordonwoody645
    @g.gordonwoody6456 жыл бұрын

    Julian - thank you for putting this together. You hit all the marks for content, organization, illustration, and narration. I'll never look at the head sail again without thinking about separation. I'm pretty sure the main sail gets involved with the flow as well, do you cover that in any of your lessons? Thanks again - subscribed!

  • @AndyMillerPhotoUK
    @AndyMillerPhotoUK3 жыл бұрын

    Very good thanks -- I need to watch it a couple of times to work out how to apply.

  • @kimchambers6685
    @kimchambers66855 жыл бұрын

    Excellent!! Thank you!

  • @fredericl6190
    @fredericl61904 жыл бұрын

    Hello Julian, you have done some of the best explanations about sailing. But your last ones were made almost two years ago... are you going to produce some more? Thank you really much.

  • @cjmac8233
    @cjmac82334 жыл бұрын

    Great explanation

  • @liasxtube
    @liasxtube6 жыл бұрын

    Very helpfull. Just bought a boat and relearning.

  • @steeniversen6768
    @steeniversen67682 жыл бұрын

    Really good go at a thorough explanation of it. Even if I think you may have time to think some things through.

  • @Argo_III
    @Argo_III5 жыл бұрын

    Nicely done

  • @FernandoLXIX
    @FernandoLXIX8 ай бұрын

    Awesome

  • @JSBax
    @JSBax3 жыл бұрын

    Are you sure about your high/low pressure areas over a sail? I would have thought the area behind a stalled sail would be low pressure, hence why the telltales get sucked back. Which is basically what a spinnaker does, right? It's a permanently stalled sail. I can't see any way to interpret the wind lines separating than to say it's lower pressure because there are clearly less air molecules in that area. I think the lift perp to wind is better illustrated by the net flow of air downward (opposite action), as a result primarily of the windward lines being pushed down by the sail angle

  • @shuajackson615

    @shuajackson615

    Жыл бұрын

    I believe you're essentially right. As I understood, it's not that there is less air in that zone, but rather fast/turbulent currents of low pressure circulating in that area. The streamlines just don't seem to reflect that aspect. Check out actual wind tunnel videos and images and you'll see what I mean. If it were high pressure then that would not create the pressure drag that we see, since the windward side of the foil would be high pressure as well

  • @user-cs5hv3eg2i
    @user-cs5hv3eg2i4 жыл бұрын

    the best

  • @triton20101
    @triton201015 жыл бұрын

    Test

  • @BrooklyFire
    @BrooklyFire4 жыл бұрын

    why am i waching sailing theory than my course chemestry theory?

  • @sissycrystobal2632
    @sissycrystobal26322 жыл бұрын

    Redo vid edit out pen selection - ask your mommy what a centroid is - moment arm too - then leave her basement