How do i calculate maximum hull pressure resistance?
965157
Here is a cached page from an MIT project that contains info. and formulas. You will need to go to the page to see the formulas because they are images and cannot be cut and pasted here.\n\nhttp://216.239.51.104/search?q=cache:tTGUiKMyOvsJ:web.mit.edu/12.000/www/m2005/a2/finalwebsite/equipment/transport/Hull.shtml+submersible+hull+pressure+resistance&hl=en&gl=us&ct=clnk&cd=1&client=firefox-a\nPressure Hull\nPressure Hulls – the structure that provides the occupants of an underwater submersible with a dry, pressure resistant habitat.\n\n   1. Shape - The pressure hull consists of spherical or cylindrical shapes in various combinations. Table 1 illustrates the advantages and disadvantages of various pressure hull shapes.\n\n      Table 1. Advantages and Disadvantages of Submersible Pressure Hull Shapes\n      Shape \n\n      Advantages\n      \n\n      Disadvantages\n      Sphere\n      \n         1. Most favorable weight to displacement ratio\n         2. Thru-hull penetrations easily made\n         3. Stress analyses more accurate and less complex\n      \n         1. Difficult and inefficient interior arrangements\n         2. Large hydrodynamic drag\n      Ellipse\n      \n         1. Moderate weight to displacement ratio \n         2. More efficient interior arrangements than in sphere \n         3. Thru-hull penetrations easily incorporated\n      \n         1. Expensive to construct \n         2. Difficult to perform accurate structural analysis\n      Cylinder\n      \n         1. Inexpensive to construct \n         2. More efficient interior arrangements than in ellipse\n         3. Low hydrodynamic drag\n      \n         1. Least efficient weight to displacement ratio\n         2. Interior frames required to increase strength\n\n   2. Materials\n\n      The selection of an appropriate pressure hull material is based on the following criteria:\n\n         1. Corrosion Resistance – the ability of a material to resist its deterioration by chemical or electrochemical action within its environment.\n         2. Resistance to Stress-Corrosion and Cracking – the ability of a material to resist failures caused by the combined action of a flaw (e.g. a crack) and tensile stress.\n         3. Resistance to Low Cycle Fatigue – the ability of a material to withstand localized fluctuating stress.\n         4. Creep Resistance – the ability of a material t withstand permanent deformation over time.\n         5. Stress Relief Embrittlement – the process by which localized residual stresses in a metal are reduced by the reduction in the normal ductility when a metal is heated to a suitable temperature and slowly cooled.\n         6. Resistance to Brittle Fractures – the ability of a material to resist failures with little or no plastic deformation.\n         7. High Strength to Density Ratio – the material must be strong and light.\n         8. High Ductility – the ability of a material to deform plastically without fracturing.\n         9. Fracture Toughness – the ability of a cracked material to resist catastrophic propagation of cracks.\n        10. Weldability – the property of a material which allows it to be welded under normal conditions.\n        11. Formability – the ability of a metal to be shaped through plastic deformation.\n\n          Submarine pressure hull are usually made of steel, aluminum, titanium, acrylic plastic and glass. However, the most widely used material is steel, because of a high degree of knowledge available to designers and manufacturers as well as of its outstanding performance in the ocean.\n\n          Aluminum is generally considered unacceptable as a pressure hull material because it is unweldable and is subject to stress-corrosion cracking. Nevertheless one solution would be to bolt the hull together instead of welding and anodize it to resist stress-corrosion cracking. Pure titanium is too susceptible to stress-corrosion at high tensile stress levels, but titanium graphite
845517
One way is to use the Clausius-Clayperon Equation.  See the link below and use the boiling point of water for one of the pressure and temperature pairs.  \n\nP.S.  It's equation 22 in the linked document.
893701
v(m/s) = Q(m3/s) / Nozzle Area(m2)
984213
http://en.wikipedia.org/wiki/Pressure_gradient_force\nhttp://en.wikipedia.org/wiki/Temperature_gradient\nHope this helps, good luck!
856026
Use the gas law\nPV=nRT
1078399
i'm not very sure if this is what you're looking for, but for a closed system with constant temperature, pV=p'V'. since volume, V = pi x (diameter/2)^2 x length, with constant length of the pipe, we have V = k(diameter)^2, where k is constant. hence, pV=p'V' is rewritten as p(diameter)^2 = p'(diameter')^2, i.e. p'/p =(80/250)^2. the new pressure is 0.1024 the original pressure.
767660
A rocket is subjected to four forces in flight; weight, thrust, and the aerodynamic forces, lift and drag.\n\nat rest I will denote the launch pressure by the symbol ps. The pressure exerts an equal force on all sides of the pressure vessel, the cone of the engine. Because the rocket is free to move along the launch mechisims, the pressure exerts a vertical force given by: \n\nFp = (ps - po) * A \n\nwhere Fp is the pressure force, po is the atmospheric pressure, and A is the cross-sectional area of the rocket tube. The net force acting on the rocket is the difference of the vertical pressure force and the weight W of the rocket: \n\nFnet = (ps - po) * A - W \n\nTo simplify the analysis, we are going to assume that the length of the launch tube is small relative to the length of the rocket. As the rocket moves, the pressure remains fairly constant inside the tube. In reality, there is a slight decrease in pressure as the volume increase, but we are going to neglect that effect to simplify this analysis. With a constant pressure, and constant pressure force, we can use a simple algebraic form of Newton's second law to determine the acceleration a, velocity v and the distance y which the rocket moves along the launch tube: \n\nFnet = m * a \n\nm * a = (ps - po) * A - W \n\nwhere m is the mass of the rocket This equation can also be written as: \n\nW * a = g * ((ps - po) * A - W) \n\nwhere g is the gravitational acceleration, which is equal to 32.2 ft/sec^2 or 9.8 m/sec^2 on the surface of the Earth. The value of g is different on the Moon, and on Mars. The weight W is equal to the mass times the gravitational acceleration. Now divide both sides by the weight to determine the rocket acceleration along the launch tube: \n\na = g * ((ps - po) * A / W - 1) \n\nFor a constant acceleration, the velocity v and distance traveled y are given by: \n\nv = a * t \n\ny = .5 * a * t^2 \n\nwhere t is the time. Using the length of the launch tube L, we can now solve for the lift off time - TLO by using the second equation: \n\nTLO = sqrt (2 * L / a) \n\nand then using this time, we can use the first equation to solve for the velocity at the end of the tube: \n\nv = TLO * a \n\nv = sqrt ( 2 * L * a) \n\nAs the rocket clears the end of the launch tube (t = TLO+), the air inside the rocket, at pressure ps, will rush out the exit and the pressure will equalize with free stream inside the tube. In reality, this will provide an additional amount of thrust T given by: \n\nT = m dot * Ve \n\nwhere m dot is the air mass flow rate out of the tube, Ve is the exit velocity of the air. For an air rocket, with no nozzle and small volume, this additional thrust is small relative to the weight of the rocket, and we will ignore this effect. \n\nThe velocity v at the end of the launch tube is used as the initial velocity in the flight equations to determine the flight trajectory of a rocket.
278765
Typical pressures for brackish water range from 225 to 375 lbf/in² (1.6 to 2.6 MPa). In the case of seawater, they range from 800 to 1,180 lbf/in² (6 to 8 MPa).
751049
First find Vo:  Vo^2 = Rg/sin(28)  Where R = range & 8 = theta\n\nUsing your numbers, Vo = 41.523 m/s\n\nImpulse = change in momentum ----> Ft = mVo---> F = mVo/t\n\nSo, F = (.0431kg*41.523m/s)/.00438sec = 408.59 N\n\nVoila!
273013
Go to the link below and it has an online calculator for pump affinity laws.  \n\nThe one you are interested in is:\n\n(pressure at old speed)/(pressure at new speed) =\n\n(old speed/new speed)^2\n\nIncrease the speed (RPM) of the pump 10%, and the discharge pressure goes up 21%    \n( 1.10^2)
563919
Assuming that the cardboard is water tight:\n\nBuoyancy force = Weight of water displaced\n\n(mass of boat)*g = (desity of water) * 4ft*5ft * height * g\n\n81820g = 1g/cm^3 * 18581 cm^2 * height\n\nheight = 4.4 cm, which is the waterline when the boat weighs 180 pounds.\n\nYeah, it sounds quite unbelievable, but most boats that large with a height of 1 foot can hold over 1100 pounds of weight before completely sinking.
1006839
if u recollect the equation,\n             resistance (r)= pl/A;\n        where p=specific resistivity\n                   l= length\n                   A= cross sectional area \n               Area = pie(3.414) * r2\n                  \n              but diameter is twic the radius.\nhence insulation thickness is dependent on pipe diameter.
322427
It depends on the area that it will span.\n\nAt 200 feet, the pressure is about 100 psi.  So, you need a glass surface that can withstand 100 psi.\n\nIn addition to pressure, the span of the glass will determine the thickness as well.\n\nFor example: a 6" diameter porthole at 100psi, it will need to be 0.6 in thick.\n\nMake it 9" diameter, and now it needs to be 0.9 in thick.\n\n\nIt seems that you roughly need an inch of thickness for every inch of radius at 1000psi, or an inch of thickness for every ten inches of radius at 100psi.  But this would be a very rough estimate.\n\nHere's one calculator I found:
532726
CW= PW / (.5)(A)(Gr)(vcubed)\n\nCW=drag coefficient\nPW= aerodynamic power (kilowats)\n.5= constant\nA= total front area of the vehicle in meters squared.\nGr= gradient of the terrain.\nv3= velocity cubed.\n\nGr can be found with the equation:\nGR=(mass)(gravity)(velocity)(sin of the angle of the gradient)\n\nyour total answer should be  no more than 1
110129
The selection of the best propeller is a combination of many different factors, such as type of boat, L.O.A of boat, type of hull, use and performance (i.e.: better top end speed or increased load carrying performance?)\nFirst of all, for an engine like this I would recommend a stainless steel propeller. SS propellers are stronger than most all other propeller materials with main advantages: longer life and high hydrodynamic efficiency derived from stiffer blades.\n\n To select the optimum propeller for the use of your boat and motor combination, you should make some test runs, keeping the following guidelines in mind: \n-Have a selection of propellers to test with. \n-Use an accurate tachometer to measure RPM. \n-Use an accurate speedometer or some means (i.e.: G.P.S.) to measure boat speed. \n-Safely test each setup at W.O.T. \n-Make sure every test is with "identical" settings. (i.e.: Boat load, trim angle, engine height, water conditions, etc.) \nSince Yamaha 250 is a power trim equipped engine, it should be tested at optimum trim angle which is the highest trim position that can be run without excessive venting (slippage) either in a straight line or in turns. \n\nSelecting the right propeller while testing, you must have in mind that:\n-Engine RPM at W.O.T. must be within the recommended operating range with the rated horsepower RPM as the target number (see specification in Operator's Manual). \n-Increasing or decreasing propeller pitch directly affects engine load throughout its RPM range. \n-A high pitch and/or diameter propeller on an engine, will result in lower engine RPM throughout its entire RPM range for a given throttle setting. \n-A low pitch and/or diameter propeller on the engine, will result in higher engine RPM throughout its entire RPM range for a given throttle setting. \n-A boat's hull design --and condition-- may limit its overall performance. \n-Transom height, transom angle and engine trim angle, all affect propeller performance. \n-Atmospheric pressure, temperature, and humidity also affect engine performance, which directly affects propeller performance. \n-Salt water is more buoyant than fresh water; this may cause some hulls to run faster than identical freshwater setups. \n-Water and wind conditions can play a big part in boat performance and propeller efficiency. \n-The boat's load and position of the load can significantly affect performance.\n\nGenerally, the rule of the thumb is that the correct size propeller will provide the best overall fuel economy and performance.\nIf I could have some more data, I think I would be able to give a couple of suggestions concerning number of blades, pitch and diameter for your engine/boat combination.
1149287
pV = n R T => if pressure is constant => p = n R T / V = const. => p / n R = T/ V = const.\n=> T / V = const.\nT1 = 333 K\nT2 = 533 K\nV1 = 0.2 m3\n\nT1 / V1 = T2 / V2 =>\nV2 = V1 x T2 / V2 = 0.2 x 533 / 333 = 0.32 m^3\nanswer D is correct
710153
Usually psi (pounds per square inch).\n\nAloha