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  • Users: LNGuy
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  1. LNGuy

    Floating Hull FEA Analysis

    As regards the modelling of the boundary condition I adopted the following conditions:(sort of pinned ends) Left node => Ux=Uy=Uz=URy=URz=0 Right node => Ux=Uy=URy=URz=0, where x=transverse axis, y= vertical axis, z=longitudinal axis, The box cross-section lying in the X-Y plane. It seems to be...
  2. LNGuy

    Floating Hull FEA Analysis

    How do we apply the self load of a beam?
  3. LNGuy

    Floating Hull FEA Analysis

    And the figure showing the MPC point is as shown here.http://files.engineering.com/getfile.aspx?folder=e397d518-4f95-4ce7-acf8-9b8a898e6e51&file=FEA_Box.png
  4. LNGuy

    Floating Hull FEA Analysis

    I have used purely elastic material with E=210000 and mu=0.3 as prescribed by the paper. Yes it caves in but I want to focus on the bending. I have used static,Riks step to deal with bending. I am applying the tie constraint on the MPC point. Kindly find attached the input file...
  5. LNGuy

    Floating Hull FEA Analysis

    I am trying to simulate what has been done in the paper. The paper shows the longitudinal bending of the hull. However, when I apply the same boundary conditions as prescribed, I am getting the bottom plating caving in (which is expected as the pressure is acting from below). So, I am not sure...
  6. LNGuy

    Floating Hull FEA Analysis

    Hi, I am doing my first academic project using Abaqus. I am trying to model a floating box hull with water pressure acting from the bottom and the sides. I am trying to follow the paper attached here. I am having problem setting the boundary conditions even though I am setting it up as per the...
  7. LNGuy

    Modelling of floating box using Abaqus

    Hello people, I am new to Abaqus and am doing an academic project on floating structures. I am trying to model a simple box floating in water and study the bending moment due to self weight. I am not able to get how to apply the boundary conditions. I am referring the attached paper which, as...
  8. LNGuy

    Ship hull bending analysis

    thread727-317253 Hell people, I am newby to Abaqus, never used it before, and have taken up a project to do bending moment analysis for a ship hull, focusing primarily on mid-ship position. I will first do it for ship's self weight and then place weights at different locations along the length...
  9. LNGuy

    temperature drop in one hour in a LNG tank

    No. In---M_tank*Cp*dT ---Cp is the specific heat of the material you are extracting heat from, here the tank, say steel. In---(m*L + m*Cg*dT'), L is latent heat of LNG and Cg is the specific heat of the vaporized LNG (gas form).
  10. LNGuy

    temperature drop in one hour in a LNG tank

    From the (Q=m*L + m*Cg*dT'), take out common m to get m=Q/(L+Cg*dT'). Not just from m*L. Your equation should essentially be: M_tank*Cp*dT = (m*L + m*Cg*dT')= m*(L + Cg*dT')
  11. LNGuy

    temperature drop in one hour in a LNG tank

    At this stage I can only explain that you find the heat to be extracted from the tank using M_tank*Cp*dT, where dT is your desired temperature drop per hour needed, say 10 degrees (from 25 C to 15 C). Then you equate this to (m*L + m*Cg*dT'), where m is the mass of the liquid(LNG) required to be...
  12. LNGuy

    temperature drop in one hour in a LNG tank

    So, start with your limiting criterion that you do not need a drop of more than 10 degrees per hour and then do calculations accordingly.
  13. LNGuy

    temperature drop in one hour in a LNG tank

    Hi, There will be a lot of factors coming into play. First of all, as per regulations there should not be a drop of 10 C per hour, so your first calculation should be based on a dT= 1 hour. Then you should find how much liquid you should pump in to extract the above heat. Another interesting...
  14. LNGuy

    temperature drop in one hour in a LNG tank

    Additionally, I was doing calculation on the very first loading of a newly built LNG vessel where there is no LNG to pre-cool it before the actual LNG starts being pumped in.
  15. LNGuy

    temperature drop in one hour in a LNG tank

    Thank you people for the response. As of now, yes LNG tanks are spray cooled before gradually increasing the LNG inflow. I did some rough iteration in excel and find that the rate of temperature drop for a 12000 m3 tnk is almost 10 degrees per hour. So, it makes the calculation a bit easier...
  16. LNGuy

    temperature drop in one hour in a LNG tank

    Thank you EmmanuelTop for your post. I am reading those links. Posted here in response to the other suggestion to post it on this forum. The papers you suggested look good. Will update here. Thanks.
  17. LNGuy

    temperature drop in one hour in a LNG tank

    Hi, I am working on calculating the gas rate formation in a tank into which LNG is being filled. I want to calculate the heat going into the LNG at -163 from the natural gas vapor existing at a high temperature initially, say +20 degrees, in one hour. For this purpose, I am focusing on...
  18. LNGuy

    temperature drop in one hour in a LNG tank

    Hi, I am working on calculating the gas rate formation in a tank into which LNG is being filled. I want to calculate the heat going into the liquid LNG at -163 from the LNG vapor existing at a high temperature initially, say +20 degrees, in one hour. For this purpose, I am focusing on...

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