Design Report Guided Missile Submarine SSG(X) - AOE - Virginia ...
Design Report Guided Missile Submarine SSG(X) - AOE - Virginia ...
Design Report Guided Missile Submarine SSG(X) - AOE - Virginia ...
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<strong>SSG</strong>(X) <strong>Design</strong> – VT Team 3 Page 75<br />
The total SHP for the snorkel condition is the summation of the submerged SHP and the wave-induced SHP.<br />
To obtain an accurate wave induced coefficient of drag, a sixth degree polynomial is fitted to a drag curve provided<br />
by Captain Jackson’s propulsion notes. The calculation of the endurance snorkel is given in Figure 70.<br />
Snorkel Ra nge:<br />
SHPsnrkv = 797.568kW<br />
Froude # for Cdw Coef Calc:<br />
Vesnork<br />
Fn<br />
( g⋅LOA) .5<br />
:=<br />
CDW 3561.3Fn 6<br />
⋅ 8812.6Fn 5<br />
− ⋅ 8148.4Fn 4<br />
+ ⋅ 3454.3Fn 3<br />
− ⋅ 654.09Fn 2<br />
:=<br />
+ ⋅ − 40.235Fn ⋅ + .2726<br />
CDW = 1.25<br />
CW :=<br />
4⋅<br />
Wave Induced:<br />
SHPW CW⋅S⋅ρSW Vesnork 3<br />
:= ⋅<br />
SHP Snorkel:<br />
SHPsnrk := SHPsnrkv + SHPW<br />
Endurance Snork Calculation:<br />
FRSPsnk := f1⋅SFCsnk FRAVGsnk := 1.05⋅FRSPsnk PsnkAVG :=<br />
Esnork :=<br />
⎡⎛<br />
⎢⎜<br />
⎣⎝<br />
LOA<br />
D<br />
⎞<br />
⎟<br />
⎠<br />
CDW<br />
− 1.3606<br />
SHPsnrk + KW24AVG<br />
ηelec<br />
Fn = 0.227<br />
⎤ ⎛<br />
⎥⎦ ⎜<br />
⎝<br />
( )<br />
Wfsnk⋅Vesnork⋅TPA PsnkAVG⋅FRAVGsnk LOA<br />
D<br />
⎞<br />
⎟<br />
⎠<br />
2<br />
CW 7.355 10 4 −<br />
= ×<br />
SHPW = 327.351kW<br />
SHPsnrk = 1125kW<br />
FRSPsnk 0.495 lbf<br />
=<br />
kW⋅hr FRAVGsnk 0.52 lbf<br />
=<br />
kW⋅hr PsnkAVG = 1878hp<br />
Esnork = 5612nm<br />
Figure 70 - Calculations for Snorkel<br />
The snorkel range does not meet the ORD requirement. Including the wave-induced drag increased the power<br />
required by 300 kW. Forty long tons of fuel were added to satisfy the requirement. The last equation in Figure 70<br />
shows the calculations performed after the fuel was added so that the range now meets the required value.