Monday, December 8, 2008
disisme Misfit talk - Apparent wind and the ACJ2.5
[12:00] disisme Misfit shouts: Wlcome to the 2008 Tradewinds Yacht Club boat show. I am dis, the sim patron, and one of the co-ordinating team behind this massive event.
today, I will speak to you about apparent wind, versus true wind....TWA and TWD
There are several boats on the market using apparent wind. But just what IS apparent wind? Apparent wind is the direction the wind SEEMS to be coming from...rather than the TRUE wind direction.... its like standing around the corner of a wall on a windy day...the wind hits you, all beint diminished, from a different direction from where it is really blowing from
Apparent wind on a boat, is affected by heading, and the speed of the boat..... heading meaning the head to wind angle..HTW
[12:04] disisme Misfit shouts: As you go faster, the wind SEEMS to be swinging more towards the bow of the boat....that is part of the physics of movement....you move in still air, you feel a breeze... While the fizz and trudeau boats have used apparent wind for a while...and the Jangars...sorry caf... most of these boats are light weight, big sails....
they accelerate fast to peak speed...
[12:05] Caf Binder: :-)
[12:05] disisme Misfit shouts: so you see the wind direction seeming change really quickly after you THINK you set the right course... that is because the boat accelerates quickly, and the apparent wind angle changes REALLY fast... The ACJ2.5 makes this all much clearer and obvious it is a big boat....over 70'..and while it accelerates REALLY fast, the transition in apparent wind is MUCH more obvious
[12:07] LiLing Qunhua: ahhhh
[12:07] disisme Misfit shouts: let say you are starting with a Head to wind of 40 degrees...standing startsails should be set to what? anyone?
[12:07] Fooh Ling: 20
[12:07] Quirky Torok: 20
[12:07] Glorfindel Arrow: 20
[12:07] LiLing Qunhua: 20
[12:07] disisme Misfit shouts: right....
[12:08] disisme Misfit shouts: in a True wind boat..like a tako.....you would set it at 20, and have optimal performance I call those the sit, turn, set, sit type of boat you sit there and do pretty much nothing till its time to turn again if you have a constant wind
[12:08] LiLing Qunhua: lol
[12:08] disisme Misfit shouts: in an apparent wind boat...that is NOT the case yes..yuou would start at 20.... but as the boat starts moving, holding the EXACT same course, the wind angle lowers
[12:09] disisme Misfit shouts: ((not cutting an pasting here..this is totally ad lib))
[12:10] disisme Misfit shouts: soon, you see the wind angle...TWA....is at 20, NOT 40... the TWD..true wind direction is still at 40 you started with sails at 20....but now the apparent wind is at 20...what’s gonna happen?
[12:11] Kaylin Bechir: you stop
[12:11] LiLing Qunhua: stop?
[12:11] Glorfindel Arrow: slow
[12:11] Quirky Torok: panic
[12:11] LiLing Qunhua: haha
[12:11] Kentrock Messmer: Open a beer.
[12:11] disisme Misfit shouts: you will slow, or reach a terminal velocity far less than the boats capability so you need to trim your sails in as you go faster.... trim back to 10..... you are now at 20 TWA...sails at 10...what happens?
[12:12] disisme Misfit shouts: the boat speeds up
[12:12] LiLing Qunhua: you go faster?
[12:12] disisme Misfit shouts: what happens when the boat speed up?
[12:12] Charlz Price: you win
[12:12] Quirky Torok: usually crash :(
[12:12] Glorfindel Arrow: TWA lowers
[12:12] disisme Misfit: hahaha , yes TWA lowers
[12:12] Gordon Goodrich: <---sir crash-a-lot
[12:12] Sana Bebb: =^.^= ****** =^.^=
[12:13] disisme Misfit shouts: so you are now with sails at 10...TWD still 40....TWA is 14.... trim.....trim...trim.... trim your sails in...: with TWA at 14..your optimal sail position is 7 trim them in....you speed up.....your TWA comes down....
[12:14] disisme Misfit: trim again....
[12:14] disisme Misfit shouts: at some point, you WILL reach a terminal velocity with the ACJ2.5 on a TWD of 90 and 21.3 knots...that terminal velocity is WELL in excess of 26 knots
[12:15] Glorfindel Arrow: I was wondering...you never get to zero then...lol
[12:15] disisme Misfit: no glor... if you leave your sails at 20 at the start.... and dont trim in...what will happen?
[12:15] Charlz Price: you get passed
[12:16] disisme Misfit: very quickly
[12:16] disisme Misfit shouts: what happens is...the boat accelerates....it gets to a point where that is peak performance ...the sails will luff, and the boat will slow. then the sails will stop luffing...and you will speed up again....
[12:16] Kentrock Messmer: How many have been sold?
[12:17] disisme Misfit shouts: half a dozen in the past 12 hours
[12:17] Kentrock Messmer: Total?
[12:17] disisme Misfit shouts: they were only released yesterday kent, launched here..
[12:18] disisme Misfit shouts: now...with the ACJ2 being a little slower to accelerate than the small boats using apparent wind to date.... you find yourself trimming it progressively...
[12:18] Kentrock Messmer: So are you going to have class racing?
[12:18] disisme Misfit: hopefully kent
[12:18] disisme Misfit: as you trim...it goes faster
[12:18] disisme Misfit: trim more..faster...
[12:19] disisme Misfit: this boat is a ferrari...NOT a chevy....
[12:19] LiLing Qunhua: YAY! (yay!)
[12:19] Fooh Ling: YAY! (yay!)
[12:19] disisme Misfit: a tako, bless kankers soul, is a chevy, sit, turn, set, sit
[12:19] LiLing Qunhua: and a wonderful chevy it has been, too
[12:19] disisme Misfit: this boat gives you back...10000 times over, what you put INTO it just like a Ferrari : you work it and RACE with it...it will be FAST if you sit, turn, set, sit.......it will bite you
[12:20] LiLing Qunhua: hehe
[12:20] disisme Misfit shouts: the same rules apply with the fizz, trudeaus last 4 boats... the KA, T20, leetle cat and Tahiti II work them.... they will play WITH you, not against you : you will be utterly amased how fast you can make a tahiti II go... of course...ann ACJ2.5 is going to go past like a freight train... but.....its got a spinnkaer that a Tahiiti can live in
[12:22] disisme Misfit shouts: as an aside on apparent wind.... apparent wind does NOT affect wind shadowing your shadow is cast downwind on TWD TRUE wind direction you block the air to a downwind boat...NOT neccessarily one that is 180 according yo your sail settings it is TRULY downwind the ACJ2.5 will shadow a boat up to 60 meters away the further azway, the less shadow. most boats shadow for 20 meters...
[12:24] Kaylin Bechir: will the 2.0?
[12:24] disisme Misfit shouts: no..the 2.5 only..this is new the AC boats have such massive sail area...20 meters was rubbish and laughable on a jangars...faaaantastsic... on a boat with sails you can hold a hangars race on....it was silly 60m of wind shadow is about right for a boat with sails that are...what..10 stories high?
[12:26] Jane Fossett: hans zinnemann claims the ACA1.6 shadows 75m
most boats shadow for 20 meters...
[12:26] disisme Misfit shouts: it doesn’t jane.....
[12:26] Jane Fossett: I couldn't show that either
[12:26] Jane Fossett: I got 20-34
[12:26] disisme Misfit shouts: it shadows a) in the wrong direction...and b) only on a beat....and nothing like that distance
[12:27] disisme Misfit shouts: right..me too...27-29m
[12:27] Jane Fossett: 20-24
[12:26] disisme Misfit shouts: ok....I will wrap it up with a reminder.... we did a LOT of testing on the ACJ2.5 shadowing... Please wait while your notecard is delivered. it shadows 7.5 degrees from mast centerline TRUE downwind and for 60M the shaodw AT 60m, is about 50% what it is at ..well..fender scraping distance after 60m, it is gone the downwind shadow and speed effect is astronomical
[12:28] Jane Fossett: is that realistic
[12:29] Caf Binder: still 50% at the 60 m limit?
[12:29] disisme Misfit shouts: get a boat 50m in front of you on a downwind spinnaker run.....
[12:29] disisme Misfit shouts: yes caf
[12:29] disisme Misfit shouts: and he will almost stop
[12:29] Jane Fossett: and 61 is 0%
[12:29] disisme Misfit shouts: right jane most work that way... with most its full shadow at 20, and 0 at 21 this level and range of shadowing, along with TWA, puts a whole lot of strategy into your sailing now in a big, fast boat
[12:30] Jane Fossett: not the T20 series or the Jangars
[12:30] Caf Binder: if i recalll... :) ive done around 20% at limit
[12:30] disisme Misfit shouts: shadowing on those boats is lovely jane...
[12:30] Glorfindel Arrow: dose the area of effect get smaller too, as it gets farther away??
[12:30] disisme Misfit shouts: no..ti gets wider 7.5 degrees from mast center line Glor
[12:31] disisme Misfit shouts: this give a lee bow affect...
[12:31] disisme Misfit shouts: I Think 7.5 to windward is a little harsh... and would prefer it to be 5 to windward, 10 to leeward... but its not possible with code limitations
[12:32] Caf Binder: (Well I expect we will soon have a standard on that for all boats to follow, if wanted)
[12:32] disisme Misfit shouts: right caf...that will be great in mixed boat classes..
[12:32] Caf Binder: 2009 promises :)
[12:32] disisme Misfit shouts: as to performance of the ACJ....the Apparent wind effect makes this boat SLOW on a beat compared to the ACA... at 28 TWD, it is 12 TWA and about 12 knots sails at 6 : but the polar on the ACJ2.5 swings DRAMATICALLY move to 31 TWD....boat speed is at 14.4 move to 38......boat speed is 17.7 that is based on 10m/s TWS (true wind speed) the boat likes to get off the wind..... get it to 90 TWD....48 TWA.... the boat is doing well in excess of 26 knots WITHOUT spinnaker : this boat will NOT perform under spinnaker anywhere under 130 degrees TWD
[12:35] Quirky Torok: is that going to affect sim crossings?
[12:36] disisme Misfit shouts: well...good question the boat is almost 200 prims lighter than an ACA33 out of the box, vehicle and hull are 10-2 prims 102
[12:36] disisme Misfit shouts: scripts are hyper efficient...I have beta tested this boat for months and NEVER had a sim crossing crash
[12:37] disisme Misfit shouts: I have crashed for SL stupidity reasons...but not on a boundary
[12:37] Kaylin Bechir: how does it compare to a 2.0?
[12:37] disisme Misfit shouts: 2.0....would be slower on a beat....actually..slower everywhere
[12:37] disisme Misfit shouts: oh.... actually 2.0 is faster on a run under spinnaker
[12:38] Kaylin Bechir: yay!
[12:38] disisme Misfit shouts: the ACJ2.5 is VERY pedantic about trim and keel adjustment on a spinnaker leg yes...keel adjustment... you can trim the keel for upwind and downwind get it set wrong....and watch everyone steam past
[12:39] Quirky Torok: oh jeeze more trim i can get wrong :(
[12:39] disisme Misfit shouts: like I said..this boat is VERY much a ferrari...
[12:39] Clay Ellison: lol
[12:40] Kaylin Bechir: how do you trim the keel?
[12:40] disisme Misfit shouts: you have to carreess it and DRIVE it its .1cb...centerboard command
[12:40] Kaylin Bechir: thanks
[12:40] disisme Misfit shouts: Its a boat that makes you SAIL it...not sit in it... very VERY like the T20 you HAVE to sail that boat.... or take lessons in reverse parking
[12:41] Glorfindel Arrow: lol
[12:41] Kaylin Bechir: hehe
[12:41] disisme Misfit shouts: the ACJ2.5 wont actually go backwards .... very well... but I HAVE reversed it out of berths.. that I Went into at 26 knots under spinnaker....
[12:42] Kaylin Bechir: haha
[12:42] disisme Misfit shouts: anyway... TWA..... your in a boat using apparent wind...trim that puppy your in an ACJ2, popping the spinnaker with another ACJ2.5 behind you.... time to start THINKING... cos they are gonna shadow your ass
[12:43] disisme Misfit shouts: any questions?
[12:43] Charlz Price: mod rights??
[12:43] disisme Misfit shouts: full mod sails and hull sails are single texture, by UUID in a notecard
[12:43] Kentrock Messmer: Skipper note card?
[12:44] disisme Misfit shouts: err...good question..... I Will say 'no' but could be wrong I am pretty sure thats a no where do you find info on the cb commands?
[12:44] disisme Misfit shouts: oh one thing I find really interesting... on the ACJ2.5 there are blue and orange crew positions : there are 2 orange balls.....one is the main trimmer, the other is the jib / spinnaker trimmer...
[12:45] Contra Koba: does the boat come with gesture pack?
[12:45] disisme Misfit shouts: no contra, but they are pretty easy to setup..similar to ACA gestures : if a passenger SIT on one of those positions..... the orange ones.. the skipper loses control of those sails so if someone sits on the jib trimmer balls.... that person OWNS those sails
[12:46] Kentrock Messmer: cool
[12:46] disisme Misfit shouts: the jib and spin someone sits on the main trimmer ball...that person has that sail the skipper CANNOT override them
[12:47] Kentrock Messmer: Can you hide the pose balls?
[12:47] disisme Misfit shouts: yessir.../1hide I just tell pepple to get the hell off....
[12:47] Contra Koba: so skipper and 3 person crew would be optimal for realism eh
[12:47] disisme Misfit doesnt play well with others..haha
[12:48] Kaylin Bechir: is the 2.5 a new version of the 2.0 or a new boat?
[12:48] Kentrock Messmer: Is the spinnaker shape modable?
[12:48] disisme Misfit shouts: skipper and 2 person...jib and spin are the same trimmer
[12:48] disisme Misfit shouts: no...
[12:48] Contra Koba: ah I see now
[12:48] disisme Misfit shouts: its firkin ugly isnt it....it should be wider..
[12:48] Kentrock Messmer: Yes
[12:49] Kentrock Messmer: Any chance of that happening?
[12:49] disisme Misfit shouts: lemme tell ya tho..it s big enough to get in the damn way....
[12:49] disisme Misfit shouts: not likely...
[12:49] Kentrock Messmer: Hmm
[12:49] disisme Misfit shouts: I betad this boat at beta 4... over a month ago... and it was vastly less buggy than the ACA is in its retail version.. : since then there have been 6 beta mods... most of those were on my insistence... features, rather than bug fixes... wording changes in messages.... a visual signal you were being shadowed... and the last one, made on the morning before release... was to reduce the Min HTW from 38 to 28 so you guys that raced me yesterday.... in your 22 degree sailing ACAs.... realise you were racing my beta 10 boat...
[12:52] disisme Misfit shouts: NOW I Can go 10 degrees higher on the wind...
[12:52] disisme Misfit shouts: your ass is mineeeee muahahahaaaaaaa
[12:53] disisme Misfit shouts: I was winning races with the ACAs having a 16 degreee HTW advantage guys... : this ACJ2.5 is FAST Ask glor what its like to hit a 90 degree TWD with an ACJ2.5 behind him?
[12:54] Glorfindel Arrow: yeah, she just steamed on by...lol
[12:54] disisme Misfit shouts: I think the term was "holy shit"
[12:54] Glorfindel Arrow: yep
[12:54] disisme Misfit shouts: so if you wanna RACE an AC class boat..... the aCJ2.5 is the go...
[12:55] Kaylin Bechir: will it compete in the ACA class?
[12:55] disisme Misfit shouts: if you wanna set and forget and get shadowed while your windward....ACA33 until it get numbers, I Think it will . . . . shit... you...the girl who spoke... : lol
[12:55] Kaylin Bechir: ha!
[12:55] disisme Misfit shouts: that is up to the race directors... each director will call it themselves... just make sure you ask first cos they WILL toss your ass out if you go ripping up their lovely ACAs as time goes on, ACJs will probably outnumber ACAs at the ACA races...lol and I think we should lean on MTW to get them into sail on... big boats..big sails..big spinnakers
[12:57] Kaylin Bechir: is my 2.0 going to be upgraded or do I have to buy another?
[12:57] disisme Misfit shouts: good question... no idea...
[12:58] Kentrock Messmer: Any boat show floor model deals? hehehe
[12:58] disisme Misfit shouts: surely she should offer a discount at least I bought that one already kent
[12:58] Kentrock Messmer: Dam!
[12:58] disisme Misfit: never got too many ACJ2s,: I Think I got...13 now..LMAO
[12:59] disisme Misfit: kachink....let the sales begin....
[12:59] disisme Misfit: the sails..did I mention... single texture?
[12:59] Quirky Torok: sold separately? not a cut up like the ACA
[12:59] Kentrock Messmer: Is there an ACJ group?
[12:59] disisme Misfit: yes, if you speak fluent Japanese kent
[13:00] Kaylin Bechir: hahahaaa
[13:00] Kentrock Messmer: not
[13:00] disisme Misfit: I Will ask sarah and max to move on that... I think we have numbers enough to probably host an ACJ2.5 race.... so if you get one, you wont be out there on your own... plus you get to shit on some ACAs... which is always fun...
[13:01] Kentrock Messmer: Now now Dis..lol
[13:01] disisme Misfit: haha
[13:01] disisme Misfit shouts: I will be asking for the location of sail templates I know they exist, because I have them
[13:02] LiLing Qunhua: thank you disi .. was great talk ... learned a lot
[13:02] Kaylin Bechir: Bravo! -- Cheers! - Applause!
[13:02] disisme Misfit smiles
[13:02] Glorfindel Arrow: thanks Disi
[13:02] disisme Misfit shouts: thank you all for coming...
[13:02] Katrinna Okelly: Thanks.
[13:02] Quirky Torok: /claps
[13:02] Kentrock Messmer: Dis you are a great saleswoman.
[13:02] disisme Misfit shouts: haha...
[13:02] disisme Misfit shouts: thats why I got all these clothes..
[13:03] disisme Misfit shouts: I am a bigger sucker for good hair
[13:03] disisme Misfit: ka chink
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Promotional video of AC-J2 2.5
http://www.youtube.com/watch?v=Y7O8vSvVLIM
Camera. Edit. Director
by kokoro Alcott
Max Starostin
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