inside housing length between bulkheads
MARS Power Housing OD
Modulus of elasticity
assumed inside diameter of housing
bulkhead thickness
1.0 times the max op depth
effective radius of bulkhead
Marks handbook pg. 5-52 case 1
maxium bending stress in bulkhead
max deflection of bulkhead
1 side bulkhead deflection
radius change due to pressure (from Excel spreadsheet)
length change due to pressure (from Excel spreadsheet)
diameter chage due to pressure
inside diameter at pressure
assumed inside housing length change (lenght change plus
max housing delflection on both ends - conservative)
inside length at pressure
compenstion volume guess value for iteration at fill conditions
estimated volume of electronics: boards, big yellow caps, chassis,
F.G plates, bellows mount. (didn't estimate smaller parts)
ambient volume of Fluorinert at fill conditions
volume change in housing due to
pressure changes only
Calculated Fluorinert Properties:
coefficients to calculate Fluorinert FC-77 density as function of temp (pg 10
in Fluorinert catalog
assumed initial (Fill) temp in C°
assumed final temp in C° (actual
estimated value 20° use listed value
for margin) based on thermal testing (corrected for 7°C water temp)
density of Fluorinert at initial temperature
density of Fluorinert at final assumed final temperature
mass of Fluorinert at initial temp and volume
Volume of Fluorinert at max final assumed temperature
Volume change in Fluorinert due to temperature change only
Volume change in Fluorinert due to temperature and pressure
change
check compensation guess volume required
"STANDARD BELLOWS COMPANY" INFORMATION:
This analysis below assumes that the bellows is at 1 atm air inside at the relaxed length.
Telecon with factory:
this file needs to be checked with this in mind!!!!!!!!!!!!!
bellow stroke per segment (from extended to comp.)
extended length of bellows per segment
relaxed state of bellow is approx 3/4 of extended
length
relaxed length of bellows per segment
compressed length of bellows per segment
from relaxed (not set) to
compressed
effective stroke of bellows per segment from relaxed to
compressed
effective area of bellows
stiffness of 1 segment of bellows
bellow travel required from fill conditions to hot/on at depth
number of bellows segments (10 convolutions/segment)
thickness of floating endcap flange
thickness of fixed endcap
thickness of endcap that extends in from
flange
total Relaxed length (at 1 atm pressure at fill temp)
including closed ends
total compressed length including closed ends
total allowable extended length of bellows with both endcaps
spring rate of bellow with multiple segments
Spring Force on bellows due to deflection
only at max compression
guess/input initial set point of bellows
total stroke of bellows from set point to compressed
Total volume compensation capacity of bellows from set point
intial/fill
MUST BE GREATER THAN
input air temperature inside bellows at sealing time
bellows set air temperature in °C
initial temperature at sealing of bellows
Assume 1 atm absolute pressure inside bellows at initial sealing of bellows
initial air volume inside bellows at setting
final temperature of bellows assumed same as final FC-77
in °C
Absolute Inside pressure of bellows at final temperature
Spring Force on bellows due to deflection from relaxed state (not set point to final temperature and depth (hot/on & depth)
absolute pressure of Fluorinert with 1 atm air filling of bellow
This pressure would take approximately 8 X 1/4-20UNC 6Al-4V bolts to do in air testing at
full power assuming a fluid temp change from Ti to Tf.
assume 1/4-20 bolts
assume 8 bolts
tensile stress on bolts doing in air testing assume ambient outside
pressure and T2 final temperature inside
Calculated Fluorinert Properties:
coefficients to calculate Fluorinert FC-77 density as function of temp (pg 10
in Fluorinert catalog
assumed initial (Fill) temp in C°
assumed final temp in C°
assumed worst case ice bath temperature and at no depth
density of Fluorinert at initial temperature
density of Fluorinert at final assumed final temperature
density of Fluorinert at final assumed final temperature
mass of Fluorinert at initial temp and volume
Volume of Fluorinert at cold temp and surface pressure
Volume change in Fluorinert due to temperature change only
volume change from ambient/fill to cold/off at no pressure
bellow travel from fill conditions/to cold off at no pressure
This number must be greater than
Total length of bellows at max extended position (cold &
off at ambient pressure.
total allowable length of bellows