How to draw Isobar / Pressure Bulb


Isobar/Presssure Bulb

 An imaginary line joining the points having same verticle stress i.e. same verticle pressure.

Short Notes:-
  1. The isobar is symmetrical about verticle axis (shape is like an onion).
  2. The intensity of isobar goes on decreases from top to bottom and along radial distance.
  3. The significant depth is the depth upto which 10 percent of isobar (0.1Q) is exist. It is also called as Pressure Bulb and the shape is Spacial Curve/ Lemniscate.(⩉)
Procedure To Draw Isobar.
  1. If 10% of isobar is to be drawn then (sigma) σz =0.1Q
  2. Let σz = Q÷Z² × KB , putting the value of σz in this equation, Hence KB = 0.1×Z²
  3. Assuming various values of depth (Z) and find out different KB.
  4. From Different KB Calculate various value of r/z and hence by knowing different Z find out 'r'
  5. Plot 10% of isobar by knowing different Z and r which is symmetric about verticle axis.

 ✡Suppose 90% of isobar is to plot then σz = 0.9Q.

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