Ce viteza maxima ati atins cu barca? :))
- Autor subiect agentuooo
- Dată creare
x_petrolist
x_petrolist
si intreb si io din curiozitate ...
de ce te intereseaza viteza barcii? (cu vele)
si ce fel de barca cu vele?
de ce te intereseaza viteza barcii? (cu vele)
si ce fel de barca cu vele?
Depinde de tipul barcii, in general multicocile sunt cele mai rapide. Din cauza ca majoritatea velierelor se misca in regim de deplasament si nu glisare, viteza maxima e proportionala cu lungimea la plutire. Dintre toate barcile cu care m-am dat, cea ma rapida a fost un sloop custom de 12 metri din Turcia, nu mai stiu exact viteza, dar a lasat in urma majoritatea ligheanelor de fibra.
Ma dati-i la om niste rezultate concrete poate are el ceva in cap si vrea sa-si faca anumite planuri.
Deci cum mai ziceau si altii in functie de configuratia barcii si viteza vantului si directia lui se poate admite la barcile cu panze din astea obisnuite adica pentru oameni botezati o viteza intre 5-10 noduri/h.(1nod=1860m daca mi-aduc inca bine aminte
)
Deci cum mai ziceau si altii in functie de configuratia barcii si viteza vantului si directia lui se poate admite la barcile cu panze din astea obisnuite adica pentru oameni botezati o viteza intre 5-10 noduri/h.(1nod=1860m daca mi-aduc inca bine aminte
)
1 nod este 1 mila marina pe ora adica 1 kn=1852m/h, ca sa fim exactzi
adi esti precis?
ca indata apre edith si te contrazice!:banana:verifica cu ecsactitate
:noroc:
remember?
si k tot am vb de ecsactitate ce ziceti de asta?
http://www.boston.com/bigpicture/2009/10/china_celebrates_60_years.html
:ahoy:
si k tot am vb de ecsactitate ce ziceti de asta?
http://www.boston.com/bigpicture/2009/10/china_celebrates_60_years.html
:ahoy:
Salut,
in acest caz viteza velierului are o importanta relativa deoarece deplasarea rareori poate fi ortodroma (linia dreapta), mai ales pe distante mai lungi.Deasemenea vantul are propriul sau ,,program'' care nu prea tine cont de dorintele navigatorului.Deci parcurgerea unei distante este influentata de calitatile navei,priceperea omului si mai ales directia si taria vantului.Astfel intr-o zi poti parcurge 250Mm sau nici macar doua cabluri.(pot fi chiar mai multe zile...de 0)
Cum socoteala de acasa nu se potriveste cu cea din tirg ai urmatoarele posibilitati:
1. Toate estimarile le consideri true si faci planificarea ca atare; asta inseamna ca poti avea o viteza intre 0 si 50+ kn.
2. Toate estimarile sint false si cind ai inchiriat barca ploua cu galeata, ai gale force winds si stai in bodega din marina.
3. None of the above.
4. All of the above.
:noroc:
x_petrolist
x_petrolist
citeva formule utile pentru aflarea vitezei ambarcatiunii si nu numai.
The Displacement/Length Ratio
According to Froude's Law, a boat with a long waterline will sail faster than a boat with a short waterline. That is why a-60 footer will go faster than a 20-footer. On the other hand, a boat with heavy displacement is slower than a boat with a light displacement. This is why a 50,000-pound 50-footer is slower than a 10,000-pound 50-footer on certain points of sail. (In general, a heavier boat is faster upwind in heavy air than a lighter boat because waves slow the lighter boat.)
A designer marries the length and the displacement by using the displacement/length ratio, which states that the displacement in tons divided by a fraction of the waterline length cubed equals a certain number. Written out, the formula is:
(Displacement in pounds/2240) / (LWL/100)3
This number is said to give an idea of the ability of the boat. In general, boats with a displacement/length ratio of under 70 can get on a plane in the right conditions. Most production boats have a ratio of 125 to 250. Boats that have a ratio over 250 tend to be cruisers. Long-distance cruisers may have a ratio over 300 and often up as high as 400, although a boat with that high a displacement/length ratio would be very slow in lighter winds. In order for the displacement/length ratio to give a good idea of any trends, a graph should be made by plotting displacement/length ratio against sail area.
Froude's Law also states that a displacement hulled boat will go faster than the wave length created by the hull as it moves through the water. This wave length is equal to 1.34 x LWL. In other words, a boat with a 25-foot waterline length will go no faster than 6.7 knots. Most boats can be overpowered or may sail down the back of a wave and temporarily exceed this calculated maximum, but they cannot maintain that speed unless they have a low displacement/length ratio when they plane.
The Sail Area to Displacement Ratio
This formula indicates how much sail area is available to push each pound of displacement through the water. It is non-dimensional in that sail area, which is in square feet, divided by the displacement divided by 64 to get the volume of displacement raised to the 2/3 power. This reduces the volume of displacement to a squared power so we divide sail area in square feet by another squared number. The formula reads:
Sail area (square feet) / (Displacement/64)2/3
It may also be written as:
Sail area / (Disp/64) .666
The sail area to displacement ratio generally works out to be between 14 and 30, with the highest numbers being the fastest boats in lighter winds. Boats with a high number also tend to accelerate faster and need to be reefed earlier. I generally plot this ratio against waterline length to get a graph that appears to be meaningful. If you wish, you could plot it against LOA + LWL/2 to average the overall and the waterline lengths of a boat.
Wetted Surface to Sail Area Ratio
Another formula that gives fairly good results is the wetted surface area to sail area ratio. This formula tells you how much wetted surface a boat has relative to its sail area. A boat with a lot of wetted surface is likely to be slow in light winds when sailed against a boat with low wetted surface. (In fact, in winds under 8 to 10 knots this is probably the most important ratio of all.) It is simply:
Sail area in square feet / Wetted surface area in square feet
Typically this ratio is around 2 to 6, with the lower number indicating that a boat has a lot of wetted surface relative to its sail area. A boat with a low number will be a slow light-air boat. The only drawback to this formula is that you will have a hard time getting the wetted surface ratio from the designer or builder.
Fuel to Displacement Ratio
How much fuel should a boat carry? If the boat has a generator it will require more fuel than a boat with no genset. If it is a cruising boat it will typically carry a lot more fuel. I developed a formula to compare the fuel capacity of various boats. It is:
(Fuel in gallons x 7.5 (changes gallons to pounds) x 100) / Displacement
I found that boats with a fuel/displacement ratio of under 1 percent tend to be racers and do not require a lot of fuel. Boats with a ratio of 5 to 7 percent tend to be long-distance cruisers. Most production cruisers that do not go far from shore have a ratio in the 2 to 4 percent range.
le-am gasit mai de mult intr-un articol scris de Roger Marshall pe boats.com
The Displacement/Length Ratio
According to Froude's Law, a boat with a long waterline will sail faster than a boat with a short waterline. That is why a-60 footer will go faster than a 20-footer. On the other hand, a boat with heavy displacement is slower than a boat with a light displacement. This is why a 50,000-pound 50-footer is slower than a 10,000-pound 50-footer on certain points of sail. (In general, a heavier boat is faster upwind in heavy air than a lighter boat because waves slow the lighter boat.)
A designer marries the length and the displacement by using the displacement/length ratio, which states that the displacement in tons divided by a fraction of the waterline length cubed equals a certain number. Written out, the formula is:
(Displacement in pounds/2240) / (LWL/100)3
This number is said to give an idea of the ability of the boat. In general, boats with a displacement/length ratio of under 70 can get on a plane in the right conditions. Most production boats have a ratio of 125 to 250. Boats that have a ratio over 250 tend to be cruisers. Long-distance cruisers may have a ratio over 300 and often up as high as 400, although a boat with that high a displacement/length ratio would be very slow in lighter winds. In order for the displacement/length ratio to give a good idea of any trends, a graph should be made by plotting displacement/length ratio against sail area.
Froude's Law also states that a displacement hulled boat will go faster than the wave length created by the hull as it moves through the water. This wave length is equal to 1.34 x LWL. In other words, a boat with a 25-foot waterline length will go no faster than 6.7 knots. Most boats can be overpowered or may sail down the back of a wave and temporarily exceed this calculated maximum, but they cannot maintain that speed unless they have a low displacement/length ratio when they plane.
The Sail Area to Displacement Ratio
This formula indicates how much sail area is available to push each pound of displacement through the water. It is non-dimensional in that sail area, which is in square feet, divided by the displacement divided by 64 to get the volume of displacement raised to the 2/3 power. This reduces the volume of displacement to a squared power so we divide sail area in square feet by another squared number. The formula reads:
Sail area (square feet) / (Displacement/64)2/3
It may also be written as:
Sail area / (Disp/64) .666
The sail area to displacement ratio generally works out to be between 14 and 30, with the highest numbers being the fastest boats in lighter winds. Boats with a high number also tend to accelerate faster and need to be reefed earlier. I generally plot this ratio against waterline length to get a graph that appears to be meaningful. If you wish, you could plot it against LOA + LWL/2 to average the overall and the waterline lengths of a boat.
Wetted Surface to Sail Area Ratio
Another formula that gives fairly good results is the wetted surface area to sail area ratio. This formula tells you how much wetted surface a boat has relative to its sail area. A boat with a lot of wetted surface is likely to be slow in light winds when sailed against a boat with low wetted surface. (In fact, in winds under 8 to 10 knots this is probably the most important ratio of all.) It is simply:
Sail area in square feet / Wetted surface area in square feet
Typically this ratio is around 2 to 6, with the lower number indicating that a boat has a lot of wetted surface relative to its sail area. A boat with a low number will be a slow light-air boat. The only drawback to this formula is that you will have a hard time getting the wetted surface ratio from the designer or builder.
Fuel to Displacement Ratio
How much fuel should a boat carry? If the boat has a generator it will require more fuel than a boat with no genset. If it is a cruising boat it will typically carry a lot more fuel. I developed a formula to compare the fuel capacity of various boats. It is:
(Fuel in gallons x 7.5 (changes gallons to pounds) x 100) / Displacement
I found that boats with a fuel/displacement ratio of under 1 percent tend to be racers and do not require a lot of fuel. Boats with a ratio of 5 to 7 percent tend to be long-distance cruisers. Most production cruisers that do not go far from shore have a ratio in the 2 to 4 percent range.
le-am gasit mai de mult intr-un articol scris de Roger Marshall pe boats.com
aceasta curiozitate poti sa ti-o satisfaci concret si singur accesand orice sait cu barci de vanzare.
x_petrolist
x_petrolist
Pai barcile si cind sint legate la cheu se misca. Cu Terra in jurul axei de revolutie, in jurul Soarelui, in jurul Galaxiei, etc, etc. Si-atunci care ar fi intrebarea corecta (sau concreta)?
x_petrolist
x_petrolist
ce face plictiseala din om...
cum vrei tu, numai spune o viteza MAXIMA (corecta si concreta
tin sa precizez ca nu e un concurs de masurat parti anatomice...
Lasind la o parte anatomia ... habar n-am. Nu am GPS (si nu m-am obosit s-o calculez cu alte metode) deci nu pot sa spun care a fost SOG maxim. Asta este o chestie pe care am invatat-o pe forum (speed over ground). Cred ca am atins in anumite momente viteza de chila (hull speed) care la un velier de 18 picioare nu este astronomica .... over and out ....
Baieti, cu tot respectul, dar cred ca nu sunteti velisti cei care puneti asemenea intrebari. Nu m-a interesat vreodata viteza, decat sa fie suficienta in caz de curent contrar. Cu un velier esti la dispozitia vantului, cand n-ai vant, davai pedala la motor. Daca vreau viteza, imi iau un lighean motorizat de la un broscar, si ma duc sa ma calc pe gat cu ciorile care au dat de gustul barcazelor de viteza. Sau daca vreau viteza cu vele, ma dau cu un catamaran de daysailing, windsurf, sau inchiriez pe bani grei un racer-cruiser.
In plus, chestia cu planul de drum, bazandu-te pe vant si vele, e o imponderabila. Si ca sa nu ziceti ca bat apa in piua, cea mai mare viteza pe care am avut-o cu barca mea de 6,80 m a fost pe 8 decembrie 1991 pe Dunare, era un viscol crancen cu Crivat, trebuia sa ducem barca la Siret, asa ca am ridicat vreo 4 metri de randa pe catarg, si am ajuns foarte repede la gura Siretului, viteza fata de apa cred ca a fost de maxim 7-8 noduri. Orice ai face, la un velier de agrement (nu sportiv) nu poti depasi hull speed.
Apropo, ia incercati sa puneti intrebari din-astea pe un forum de velisti de afara, sa vedeti ce usor veti invata argoul marinaresc local
.
In plus, chestia cu planul de drum, bazandu-te pe vant si vele, e o imponderabila. Si ca sa nu ziceti ca bat apa in piua, cea mai mare viteza pe care am avut-o cu barca mea de 6,80 m a fost pe 8 decembrie 1991 pe Dunare, era un viscol crancen cu Crivat, trebuia sa ducem barca la Siret, asa ca am ridicat vreo 4 metri de randa pe catarg, si am ajuns foarte repede la gura Siretului, viteza fata de apa cred ca a fost de maxim 7-8 noduri. Orice ai face, la un velier de agrement (nu sportiv) nu poti depasi hull speed.
Apropo, ia incercati sa puneti intrebari din-astea pe un forum de velisti de afara, sa vedeti ce usor veti invata argoul marinaresc local
.