This page discusses the input details of the "Segmented" Grain geometry in the Rocket Motor SimulationModule.
The Segmented grain geometry input tab is shown in the following figure.
The following categories of inputs are shown:
in the upper left hand corner.
Grain Gross Parameters in the lower left hand corner.
Grain Feature Parameters in the lower right hand corner.
Also shown in the upper left hand corner is a visualization of the grain cross section as defined by the Grain Feature Parameter inputs, along with an Update Display button used to refresh the display of the grain cross section, if required.
The Propellant Parameters inputs are:
- Rocket Grain Type: A pull down menu enabling the user to select the desired geometry. For this grain geometry select "Segmented".
- Propellant Name: A field displaying the nomenclature of the propellant grain if read in from the reference books. When propellant chemistry is loaded from reference books, that descriptor will be displayed.
- Number of Surfaces Burning: A numeric option of 0,1, or 2 to indicate the number of grain end surfaces involved in combustion. Since both ends of this grain are prevented from burning (inhibited), enter a 0.
- Number of Charges
- Propellant Erosion Coefficient
Under the Grain Gross Parameters input category:
- The Grain Length is the length of the energetic material that comprises the rocket motor grain. Here, enter 781.05 mm.
- The Grain External Diameter is the Outside Diameter, the exterior diameter of the rocket motor grain. This diameter should have been passed through from the Rocket Motor Sizing Utility .
- The Grain Interior Diameter is the Interior Diameter, the interior diameter of the rocket motor grain, shown on the previous page.
- The Fraction of Propellant Gas is a scalar multiplier on the propelling gas exiting the nozzle. A number between 0.90 and 0.99 is typical.
Under the Grain Feature Parameters input category:
- Number of Grain Segments, is the number of section features for the grain being analyzed. This is an integer value. Generally, if the burning surface area requirements can be met with an odd number of features, this is preferred as an odd number prevents combustion instabilies arising from acoustic sources.
- The Clearance Between Grain Segments is the X0 dimension, the clearance between adjacent grain segments.
Top
Previous
Next