Old wives tale??

  • kooty
    Keymaster
    1 hour 15 mins to the Pond
    Posts: 18101
    January 20, 2012 at 12:10 am #1303450

    I’ve been told when it’s below 0, ice can form as much as 6 inches in 24 hours. What “rate” have you heard before?

    biggill
    East Bethel, MN
    Posts: 11321
    January 20, 2012 at 12:15 am #1030209

    It would depend on how thick it is. It would also depend on how much covers are on top.

    From what I’ve heard, 6″ is the average…

    biggill
    East Bethel, MN
    Posts: 11321
    January 20, 2012 at 12:24 am #1030212

    Did I say covers? I meant snow cover.

    Seriously though, I would really have to say that every body of water would be significantly different. Currents, depth, wind, snow cover, ice thickness would be significant factors. In order to make ice on a lake, a huge mass of water would have too cool down in that period of time.

    6″ in 24 hours sounds to me like maximum potential.

    rvvrrat
    The Sand Prairie
    Posts: 1840
    January 20, 2012 at 12:28 am #1030213

    My old wives told me 1″ per day…

    JiNormal
    Princeton, MN
    Posts: 5
    January 20, 2012 at 12:29 am #1030214

    Well I’ve heard elephants need 4 feet, but then I guess 6 inches wouldn’t be enough.

    gary_wellman
    South Metro
    Posts: 6057
    January 20, 2012 at 12:37 am #1030219

    Quote:

    My old wives told me 1″ per day…

    yup. 1″ ice a day at below zero when ice is already established.

    out_fishing
    Moorhead, MN
    Posts: 1151
    January 20, 2012 at 3:00 am #1002461

    X3 or so on the inch a day…

    weldon
    Rochester, Mn
    Posts: 304
    January 20, 2012 at 6:29 am #1030300

    Had to search a bit for this and found a textbook on Google that included the equation on pages 186 & 187 for the adventurous reader…

    Introduction to Cold Regions Engineering

    X = 0.983 * sqrt(deg F * Day) where X is in inches

    This is for the simple case where there are no currents or ice does not have bubbles and no sublimation (evaporation) at the surface is assumed using Stephan’s equation.

    The rate of thickness growth depends on the transmission of the heat given off through the ice layer above. When water freezes it gives off heat (1200 BTU/gallon) called the heat of fusion. The rate of ice formation is relatively quick initially and each subsequent amount of thickness is a function of the square root of “time x temperature difference” where time is in days and temperature differential is between the top and bottom of the ice layer in degrees Fahrenheit.

    An example is that with 31F air temperature and water at 32 degrees the first inch of ice is formed in one day. It would take 4 days for the 2nd inch of ice to form and yet another 6 days to reach the thickness of 3 inches.

    Higher difference in temperature results in faster rate of growth. Because there is this squared factor of the two properties, I made up a small table for the ice thickness displayed in inches.

    rvvrrat
    The Sand Prairie
    Posts: 1840
    January 20, 2012 at 2:04 pm #1030404

    Leave it to an engineer to introduce physics and take the wives out of the picture

    mower
    Wisconsin, Outagamie
    Posts: 515
    January 20, 2012 at 5:15 pm #1030541

    Weldon, you lost me. Can you put that in English please??? Something my wife can understand.

    clicker
    Posts: 130
    January 20, 2012 at 5:32 pm #1030558

    Delta means change. So based on his table, Change in temperature in relation to hours.days of making ice.

    So as he stated

    Quote:

    example is that with 31F air temperature and water at 32 degrees the first inch of ice is formed in one day. It would take 4 days for the 2nd inch of ice to form and yet another 6 days to reach the thickness of 3 inches.

    So basically based on his table, you can have a rapid change in temperature like we have had, but that doesn’t mean in one day you are going to make a lot of ice. It takes several days.

    I think that is the concept. We would need several days of rapid cold spells to put on some ice

    mower
    Wisconsin, Outagamie
    Posts: 515
    January 20, 2012 at 6:41 pm #1030586

    I’ll just go with 1-6 inches a day. Depending on temp.

    clicker
    Posts: 130
    January 20, 2012 at 7:02 pm #1030594

    I think with the weather we are having id go with .25″ a day if that.

Viewing 13 posts - 1 through 13 (of 13 total)

You must be logged in to reply to this topic.