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parasitedrag [2019/07/08 08:10]
admin created
parasitedrag [2020/03/18 11:03] (current)
ramcdona
Line 13: Line 13:
 $ D \equiv \mbox{Diameter} $\\ $ D \equiv \mbox{Diameter} $\\
 $ X_{area} \equiv \mbox{Max cross sectional area} $\\ $ X_{area} \equiv \mbox{Max cross sectional area} $\\
- ​\equiv \mbox{Fineness ratio} $\\+FR  ​\equiv \mbox{Fineness ratio} $\\
 $ Re \equiv \mbox{Reynolds number} $\\ $ Re \equiv \mbox{Reynolds number} $\\
 $ V_{inf} \equiv \mbox{freestream velocity} $\\ $ V_{inf} \equiv \mbox{freestream velocity} $\\
Line 248: Line 248:
  
 === Body Equations === === Body Equations ===
 +
 +Slender body form factor equations are typically given in terms of the fineness ratio (FR), which is the length to diameter ratio for the body.
 +
 +$$ FR = \frac{l}{d}$$
 +
 +For bodies of arbitrary cross section, an equivalent diameter is calculated based on the cross sectional area.
 +
 +$$ d = 2 * \sqrt{\frac{A_{xsec}}{\pi}}$$
  
 == Schemensky Fuselage (9) == == Schemensky Fuselage (9) ==
Line 256: Line 264:
  
 == Hoerner Streamlined Body (1) == == Hoerner Streamlined Body (1) ==
-$$ FF = 1 + \frac{1.5}{\left(\frac{l}{d}\right)^{1.5}} + \frac{7}{\left(\frac{l}{d}\right)^3} $$+$$ FF = 1 + \frac{1.5}{\left(FR\right)^{1.5}} + \frac{7}{\left(FR\right)^3} $$
  
 == Torenbeek (14) == == Torenbeek (14) ==
-$$ FF = 1 + \frac{2.2}{\left(\frac{l}{d}\right)^{1.5}} + \frac{3.8}{\left(\frac{l}{d}\right)^3} $$+$$ FF = 1 + \frac{2.2}{\left(FR\right)^{1.5}} + \frac{3.8}{\left(FR\right)^3} $$
  
 == Shevell (15) == == Shevell (15) ==
-$$ FF = 1 + \frac{2.8}{\left(\frac{l}{d}\right)^{1.5}} + \frac{3.8}{\left(\frac{l}{d}\right)^3} $$+$$ FF = 1 + \frac{2.8}{\left(FR\right)^{1.5}} + \frac{3.8}{\left(FR\right)^3} $$
  
 == Covert (4) == == Covert (4) ==
-$$ FF = 1.02\left(1.0 + \frac{1.5}{\left(\frac{l}{d}\right)^{1.5}} + +$$ FF = 1.02\left(1.0 + \frac{1.5}{\left(FR\right)^{1.5}} + 
-\frac{7.0}{\left(\frac{l}{d}\right)^3 \left(1.0 - M^3\right)^{0.6}}\right) $$+\frac{7.0}{\left(FR\right)^3 \left(1.0 - M^3\right)^{0.6}}\right) $$
  
 == Jenkinson Fuselage (8) == == Jenkinson Fuselage (8) ==
parasitedrag.1562598621.txt.gz · Last modified: 2019/07/08 08:10 by admin