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21. STAGE SIZING FACTORS
21. STAGE SIZING FACTORS ==================================
When you click the [Stage Sizing Factors] button in a stage's 'Configure Tandem Stage'
window, the 'Sizing Factors for Stage …' window opens. If the stage is an unpropelled stage,
the only sizing factors are the stage diameter and density of the stage mass. If the
unpropelled stage is a "dummy" stage with zero 'Stage Mass', the density is meaningless and
does not appear in the sizing factors window.
The following discussion applies only to propelled stages.
If the stage is unmated or
is the base stage in a
mated group, you have
two options for sizing the
stage: Checking the
'Aspect Ratio' box and
specifying a stage aspect
ratio, or checking the
'Diameter' box and
specifying a stage
'Diameter'.
Group" will appear in the sizing factors window.
If the stage is in a mated
group but is not the
group's base stage, its
diameter will be the same
as that of the base stage,
and the message "Stage
Diameter determined by
Base Stage of Mated
The 'Aspect Ratio' is the ratio of the stage's (or mated group's) length to its diameter. The
"length" in the ratio does not include any adjunct inert mass (or payload) lengths.
'Propellant Bulk Density' is the average density of the rocket stage's propellants. It can affect
the stage diameter when the aspect-ratio sizing option is chosen and thus possibly affect the
aerodynamic force on the stage. Otherwise, 'Propellant Bulk Density' only affects the stage
length in the rocket drawing.
'Density of Primary Inert Mass' is the average density of the stage's primary inert mass. It
too can affect the stage diameter when the aspect-ratio sizing option is chosen and thus
possibly affect the aerodynamic force on the stage. Otherwise, 'Density of Primary Inert
Mass' only affects the stage length in the rocket drawing.
'Density of Adjunct Inert Mass' is the average density of the adjunct inert mass. If the stage
has no adjunct inert mass, this factor will not appear in the stage sizing window. For the top
stage, this factor always appears and is labeled 'Density of Payload'. 'Density of Adjunct Inert
Mass' only affects the stage length in the rocket drawing.
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