/* * Lighter Than Air Lift Calculator * $Source: /Users/syzdek/Sites/calculators/RCS/ltalc.js,v $ * $Revision: 1.1 $ * $Date: 2007/01/10 14:53:01 $ * $Author: syzdek $ */ /* * This script determines the volume of a gas needed to lift * a particular mass within earth's atmosphere. This script uses * the following formula's * * Ideal Gas Law: * PV = nRT * * Kelvin to Fahrenheit Conversion: * F = 1.8(K - 273.15) + 32 * */ /* * Copyright (c) 2005 David Syzdek * All Rights Reserved. * * Redistribution and use in source and binary forms, with or without modifi- * cation, are permitted provided that the following conditions are met: * * o Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * o Redistributions in binary form must reproduce the above copyright no- * tice, this list of conditions and the following disclaimer in the do- * cumentation and/or other materials provided with the distribution. * * o The names of the contributors may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LI- * ABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUEN- * TIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEV- * ER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABI- * LITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* Set Global Var Defaults */ var LTALC_outside_temperature = 75; var LTALC_outside_pressure = 1; var LTALC_inside_temperature = 75; var LTALC_inside_pressure = 14.695; var LTALC_volume = 1000; /* Set known constants */ var LTALC_atomicmass_nitrogen2 = 28.01348; var LTALC_atomicmass_oxygen2 = 31.9988; var LTALC_atomicmass_argon = 39.948; var LTALC_atomicmass_co2 = 44.0095; var LTALC_atomicmass_hydrogen2 = 2.01588; var LTALC_atomicmass_helium = 4.002602; var LTALC_aircomp_nitrogen = 0.78084; var LTALC_aircomp_oxygen = 0.20947; var LTALC_aircomp_argon = 0.00934; var LTALC_aircomp_co2 = 0.00002; var LTALC_const_ggc = 0.08205; /* General Gas Constant = 0.08205 atm dm^3 K^(-1) mol^(-1) */ var LTALC_const_lb2g = 453.59237; /* 1 lb = 453.59237 grams */ var LTALC_const_ft2dm_cubic = 28.31684387; /* 1'^3 = 28.31684387dm^3 */ var LTALC_const_psi2atm = 0.068; /* 1 psi = 0.068 atm */ /* Declare Global Vars */ var LTALC_weight_of_atmosphere; var LTALC_weight_of_hydrogen; var LTALC_weight_of_helium; var LTALC_weight_of_hot_air; var LTALC_lift_of_hydrogen; var LTALC_lift_of_helium; var LTALC_lift_of_hot_air; /* * This script assumes that the user is attempting to * determine the lift and will calculate the new lift * if any changes are made. The exception is, if a new * lift is given, the script will determine the volume * required to provide the given lift. */ /*******************************/ /* */ /* Functions to determine lift */ /* */ /*******************************/ /* calculate the lift */ function ltalc_find_lift() { /* declare local vars */ var Moles; var Volume; /* Determine volume in dm^3 */ Volume = (LTALC_const_ft2dm_cubic*LTALC_volume); /* Determine number of moles of atmosphere displaced */ Moles = (LTALC_outside_pressure*Volume)/(LTALC_const_ggc*(((LTALC_outside_temperature-32)/1.8)+273.15)); /* Determined mass of atmosphere displaced */ LTALC_weight_of_atmosphere = 0; LTALC_weight_of_atmosphere = (LTALC_weight_of_atmosphere+(((LTALC_aircomp_nitrogen*Moles)*LTALC_atomicmass_nitrogen2)/LTALC_const_lb2g)); LTALC_weight_of_atmosphere = (LTALC_weight_of_atmosphere+(((LTALC_aircomp_oxygen*Moles)*LTALC_atomicmass_oxygen2)/LTALC_const_lb2g)); LTALC_weight_of_atmosphere = (LTALC_weight_of_atmosphere+(((LTALC_aircomp_argon*Moles)*LTALC_atomicmass_argon)/LTALC_const_lb2g)); LTALC_weight_of_atmosphere = (LTALC_weight_of_atmosphere+(((LTALC_aircomp_co2*Moles)*LTALC_atomicmass_co2)/LTALC_const_lb2g)); /* Determine number of moles of gas in envelope */ Moles = (((LTALC_inside_pressure*LTALC_const_psi2atm)+LTALC_outside_pressure)*Volume)/(LTALC_const_ggc*(((LTALC_inside_temperature-32)/1.8)+273.15)); /* Determined mass of gas in envelope */ LTALC_weight_of_hydrogen = ((Moles * LTALC_atomicmass_hydrogen2)/LTALC_const_lb2g); LTALC_weight_of_helium = ((Moles * LTALC_atomicmass_helium)/LTALC_const_lb2g); LTALC_weight_of_hot_air = 0; LTALC_weight_of_hot_air = (LTALC_weight_of_hot_air+(((LTALC_aircomp_nitrogen*Moles)*LTALC_atomicmass_nitrogen2)/LTALC_const_lb2g)); LTALC_weight_of_hot_air = (LTALC_weight_of_hot_air+(((LTALC_aircomp_oxygen*Moles)*LTALC_atomicmass_oxygen2)/LTALC_const_lb2g)); LTALC_weight_of_hot_air = (LTALC_weight_of_hot_air+(((LTALC_aircomp_argon*Moles)*LTALC_atomicmass_argon)/LTALC_const_lb2g)); LTALC_weight_of_hot_air = (LTALC_weight_of_hot_air+(((LTALC_aircomp_co2*Moles)*LTALC_atomicmass_co2)/LTALC_const_lb2g)); /* Determine lift of gas */ LTALC_lift_of_hydrogen = LTALC_weight_of_atmosphere - LTALC_weight_of_hydrogen; LTALC_lift_of_helium = LTALC_weight_of_atmosphere - LTALC_weight_of_helium; LTALC_lift_of_hot_air = LTALC_weight_of_atmosphere - LTALC_weight_of_hot_air; /* exits function */ return(0); }; /* calculate the volume required to lift with hydrogen */ function ltalc_volume_from_hydrogen() { /* Declare local vars */ var Moles; /* Calculates Volume */ Moles = (LTALC_outside_pressure*LTALC_aircomp_nitrogen*LTALC_atomicmass_nitrogen2*LTALC_const_lb2g); alert("Is this the problem"); Moles = ( ((LTALC_outside_pressure*LTALC_aircomp_nitrogen)*(LTALC_atomicmass_nitrogen2*LTALC_const_lb2g)) / (LTALC_const_gcc * (((LTALC_outside_temperature-32)/1.8)+273.15) ) ); alert("Is this the problem"); //Moles = Moles - (((LTALC_inside_pressure*LTALC_const_psi2atm)+LTALC_outside_pressure)*LTALC_atomicmass_hydrogen2*LTALC_const_lb2g)/(LTALC_const_gcc*(((LTALC_inside_temperature-32)/1.8)+273.15)); //LTALC_volume = (LTALC_lift_of_hydrogen*LTALC_const_lb2g)/Moles; /* Exits function */ return(0); }; /* Sets values on form */ function ltalc_set_values() { /* Displays lift */ document.liftcalc.elift.value = (Math.round(LTALC_lift_of_helium*100)/100); document.liftcalc.ylift.value = (Math.round(LTALC_lift_of_hydrogen*100)/100); document.liftcalc.hlift.value = (Math.round(LTALC_lift_of_hot_air*100)/100); /* Displays Volume */ document.liftcalc.ivolume.value = (Math.round(LTALC_volume*100)/100); document.getElementById('ovolume').innerHTML = (Math.round(LTALC_volume*100)/100); /* Displays Temperature */ document.liftcalc.itemperature.value = (Math.round(LTALC_inside_temperature*10)/10); document.liftcalc.otemperature.value = (Math.round(LTALC_outside_temperature*10)/10); /* Displays pressure */ document.liftcalc.ipressure.value = (Math.round(LTALC_inside_pressure*1000)/1000); document.liftcalc.opressure.value = (Math.round(LTALC_outside_pressure*1000)/1000); /* Displays Weight of Envelope */ document.getElementById('yweigth').innerHTML = (Math.round(LTALC_weight_of_hydrogen*100)/100); document.getElementById('eweigth').innerHTML = (Math.round(LTALC_weight_of_helium*100)/100); document.getElementById('hweigth').innerHTML = (Math.round(LTALC_weight_of_hot_air*100)/100); /* Displays weight of air displaced */ document.getElementById('yair').innerHTML = (Math.round(LTALC_weight_of_atmosphere*100)/100); document.getElementById('eair').innerHTML = (Math.round(LTALC_weight_of_atmosphere*100)/100); document.getElementById('hair').innerHTML = (Math.round(LTALC_weight_of_atmosphere*100)/100); /* exits function */ rturn(0); }; /* Check data */ function ltalc_check_data() { /* Check Volume */ if ( isNaN(document.liftcalc.ivolume.value) ) { alert("You must enter a number value"); return(1); }; /* Check Temperature */ if ( isNaN(document.liftcalc.itemperature.value) ) { alert("You must enter a number value"); return(1); }; if ( isNaN(document.liftcalc.otemperature.value) ) { alert("You must enter a number value"); return(1); }; /* Check Pressure */ if ( isNaN(document.liftcalc.ipressure.value) ) { alert("You must enter a number value"); return(1); }; if ( isNaN(document.liftcalc.opressure.value) ) { alert("You must enter a number value"); return(1); }; /* Check lift */ if ( isNaN(document.liftcalc.ylift.value) ) { alert("You must enter a number value"); return(1); }; if ( isNaN(document.liftcalc.elift.value) ) { alert("You must enter a number value"); return(1); }; /* Save Volume */ LTALC_volume = document.liftcalc.ivolume.value; /* Save Temperature */ LTALC_outside_temperature = document.liftcalc.otemperature.value; LTALC_inside_temperature = document.liftcalc.itemperature.value; /* Save Pressure */ LTALC_outside_pressure = document.liftcalc.opressure.value; LTALC_inside_pressure = document.liftcalc.ipressure.value; /* Save lift */ LTALC_weight_of_hydrogen = document.liftcalc.ylift.value; LTALC_weight_of_helium = document.liftcalc.elift.value; }; /* Verifies that the data is correct before recalculating */ function ltalc_recalculate_lift() { ltalc_check_data(); ltalc_find_lift(); ltalc_set_values(); }; /* Verifies that the data is correct before recalculating volume from hydrogen */ function ltalc_recalculate_volume_hydrogen() { ltalc_check_data(); ltalc_volume_from_hydrogen(); alert("Got Here"); ltalc_find_lift(); ltalc_set_values(); }; /* Displays form */ function ltalc_display_form() { /* Prints Form */ document.write("
\n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); //document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); document.write(" \n"); //document.write(" \n"); //document.write(" \n"); document.write(" \n"); document.write("
\n"); document.write(" Inside Envelope\n"); document.write("     \n"); document.write(" Outside Envelope\n"); document.write("
\n"); document.write(" Volume (feet):
\n"); document.write(" Temperature (F):
\n"); document.write(" Pressure (PSI):
\n"); document.write(" 		\n"); document.write("
\n"); document.write("
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\n"); document.write(" 		    \n"); document.write(" Volume (feet):
\n"); document.write(" Temperature (F):
\n"); document.write(" Pressure (atm):
\n"); document.write(" 		\n"); document.write(" 0
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\n"); document.write(" Hydrogen\n"); document.write("   \n"); document.write(" Helium\n"); document.write("
\n"); document.write(" Weight of Air (lb):
\n"); document.write(" Weight of Envelope (lb):
\n"); document.write(" Amount of lift (lb):
\n"); document.write(" 		\n"); document.write(" 0
\n"); document.write(" 0
\n"); document.write("
\n"); document.write(" 		  \n"); document.write(" Weight of Air (lb):
\n"); document.write(" Weight of Envelope: (lb):
\n"); document.write(" Amount of lift (lb):
\n"); document.write(" 		\n"); document.write(" 0
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\n"); document.write(" Hot Air\n"); document.write("   \n"); //document.write(" Helium\n"); //document.write("
\n"); document.write(" Weight of Air (lb):
\n"); document.write(" Weight of Envelope (lb):
\n"); document.write(" Amount of lift (lb):
\n"); document.write(" 		\n"); document.write(" 0
\n"); document.write(" 0
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\n"); document.write(" 		  \n"); //document.write(" Weight of Air (lb):
\n"); //document.write(" Weight of Envelope: (lb):
\n"); //document.write(" Amount of lift (lb):
\n"); //document.write(" 		\n"); //document.write(" 0
\n"); //document.write(" 0
\n"); //document.write("
\n"); //document.write("
\n"); document.write("
\n"); }; /* LTALC init function */ function ltalc_init() { /* Draw form */ ltalc_display_form(); /* Set defaults */ ltalc_find_lift(); ltalc_set_values(); ltalc_check_data(); ltalc_find_lift(); ltalc_set_values(); };