' program balloon.bas march 25, 2017

' determines performance capability of hot air balloons

' gross weight capability, kilograms
' gas temperature required, degrees fahrenheit
' balloon volume required, cubic meters
' maximum altitude capability, meters

' MicroMite eXtreme version

''''''''''''''''''''''''''''

option default float

dim weight, volume, gastemp, altitude

dim rho, rhoamb, gtempabs, tambabs, tsiteabs

const altitude0 = 10999.9272

const rhosl = 1.22557

print " "
print "program balloon"
print "---------------"
print " "

print "please input the launch site altitude (meters)"

input altsite

print " "
print "please input the launch site temperature (degrees f)"

input tempsite

' determine launch site ambient density and absolute temperature

rho = rhosl * fnb(altsite) ^ 4.256116 / (1.0 + (tempsite - 59.0) / 518.67)

tsiteabs = fna(tempsite)

' print menu and prompt user for selection

do

print " "
print "performance menu"
print " "
print " "
print " < 1 > gross weight capability"
print " "
print " < 2 > gas temperature required"
print " "
print " < 3 > balloon volume required"
print " "
print " < 4 > maximum altitude capability"
print " "
print " "
print "selection"

input selection%

loop until (selection% >= 1 and selection% <= 4)

select case selection%

case 1

gweight

case 2

trequired

case 3

vrequired

case 4

maxalt

end select

' print results

print " "
print "program balloon"
print "---------------"
print " "
print "gross weight ", str$(weight, 0, 2), " kilograms"
print " "
print "balloon volume ", str$(volume, 0, 2), " cubic meters"
print " "
print "gas temperature ", str$(gastemp, 0, 2), " degrees f"
print " "
print "altitude ", str$(altitude, 0, 2), " meters"
print " "
print "ambient temperature ", str$(fnc(tambabs), 0, 2), " degrees f"
print " "

end

''''''''''''''''''''''

function fna(x) as float

fna = 5.0 * (x + 459.67) / 9.0

end function

''''''''''''''''''''''

function fnb(x) as float

fnb = (1.0 - 0.000022556913 * x)

end function

''''''''''''''''''''''

function fnc(x) as float

fnc = 9.0 * x / 5.0 - 459.67

end function

'''''''

sub atmos

' ambient density and absolute temperature subroutine

if (altitude < altitude0) then

a = fnb(altitude)

rhoamb = rho * a ^ 4.256116

tambabs = a * tsiteabs

else

rhoamb = 0.297122 * rho * exp(1.73454773 - 0.0001576872 * altitude)

tambabs = 216.65

end if

end sub

''''''''''''''

sub get_altitude

' request altitude subroutine

do
print " "

print "altitude (meters)"

input altitude

loop until (altitude > 0.0)

end sub

'''''''''''''

sub get_gastemp

' request gas temperature subroutine

do
print " "

print "please input the gas temperature (degrees f)"

input gastemp

loop until (gastemp > 0.0)

gtempabs = fna(gastemp)

end sub

''''''''''''

sub get_volume

' request balloon volume subroutine

do
print " "

print "please input the balloon volume (cubic meters)"

input volume

loop until (volume > 0.0)

end sub

''''''''''''

sub get_weight

' request gross weight subroutine

do
print " "

print "please input the gross weight (kilograms)"

input weight

loop until (weight > 0.0)

end sub

'''''''''

sub gweight

' gross weight capability subroutine

print " "

get_volume

get_gastemp

get_altitude

atmos

weight = volume * rhoamb * (1.0 - tambabs / gtempabs)

end sub

''''''''

sub maxalt

' maximum altitude subroutine

print " "

get_weight

get_volume

get_gastemp

x0 = 0.0

x2 = 3.0 * altitude0

altitude = 0.0

wfunction(wf0)

if (wf0 <= 0.0) then

print " "

print "cannot lift this weight !!"

exit sub

end if

do

x1 = 0.5 * (x0 + x2)

altitude = x0

wfunction(f0)

altitude = x1

wfunction(f1)

altitude = x2

wfunction(f2)

a = x1 - x0

b = f1 / f0

c = b * b - f2 / f0

x3 = x1 + a * b / sqr(c)

altitude = x3

if (abs(x3 - x2) < 0.1) then exit do

wfunction(f3)

if (f3 * f1 < 0.0) then x0 = x1

if (f3 * f2 < 0.0) then x0 = x2

x2 = x3

loop

end sub

'''''''''''

sub trequired

' gas temperature required subroutine

print " "

get_weight

get_volume

get_altitude

atmos

a = volume * rhoamb

gtempabs = a * tambabs / (a - weight)

gastemp = fnc(gtempabs)

end sub

'''''''''''

sub vrequired

' balloon volume required subroutine

print " "

get_weight

get_gastemp

get_altitude

atmos

volume = weight / (rhoamb * (1.0 - tambabs / gtempabs))

end sub

''''''''''''''''

sub wfunction (wf)

' weight function subroutine

atmos

wf = volume * rhoamb * (1.0 - tambabs / gtempabs) - weight

end sub