29d. Summary of the constraints

    The three tables summarizing the constraints for angles of 30°, 70°, and 105° are shown below. They collectively offer these important conclusions:

  1. There are no constraints on mcloud. Allowable solutions for each angle are found for the full range of 0.1–1.0 lb used.
  2. There are moderate constraints for vcloud, namely that its values for the allowable masses of head (5–7 lb, as seen under "Prescreening") do not fall below 200 ft s-1.
  3. All lurches for the acceptable heads and angles of 30° and 70° are negative. Only at the extremely wide 105° do some lurches become positive.

For Θcl = 30°

Mhead, lb mcloud, lb vcloud, ft s-1 vlurch, ft s-1 PE, ft-lb
5 0.11.0 200–600 -0.8 to -6.4 110–600
6 0.11.0 200–600 -0.8 to -5.7 110–580
7 0.11.0 200–600 -0.8 to -5.8 100–570
8 0.11.0 100–600 -0.2 to -4.7 100–600
9
10

For Θcl = 70°

Mhead, lb mcloud, lb vcloud, ft s-1 vlurch, ft s-1 PE, ft-lb
5 0.11.0 200–600 -0.2 to -3.8 110–540
6 0.11.0 200–600 -0.2 to -3.4 110–590
7 0.11.0 200–600 -0.2 to -3.5 110–580
8 0.11.0 100–600 +0.1 to -2.9 110–590
9
10

 For Θcl = 105°

Mhead, lb mcloud, lb vcloud, ft s-1 vlurch, ft s-1 PE, ft-lb
5 0.11.0 200–600 +0.4 to -1.3 110–540
6 0.11.0 200–600 +0.4 to -1.1 130–590
7 0.11.0 200–600 +0.3 to -1.2 120–580
8 0.11.0 100–600 +0.3 to -1.1 100–590
9
10

The pseudo-inverse relation of mcloud and vcloud
    The previous three subsections have revealed a pseudo-inverse relation between mcloud and vcloud. Here we explore this relation directly to see how close it comes to being inverse.
    The easiest way to show the relation is in a simple table of mcloud and vcloud. We do this below for Θcl = 70°, PE = 300 ft-lb, dsnap = 2.4 in, and mhead = 5 and 6 lb, as calculated with SL6A. The results show that for both heads, increasing mcloud by 10x decreases vcloud by 3x. This makes their product increase by 3x. Thus vcloud changes by one-third as much as mcloud (and in the opposite direction).

Mhead, lb mcloud, lb vcloud, ft s-1 mcl x vcl Mhead, lb mcloud, lb vcloud, ft s-1 mcl x vcl
5 0.1 713.2 71.3 6 0.1 689.8 69.0
  0.2 504.2 100.8   0.2 487.6 97.5
  0.3 411.5 123.4   0.3 398.0 119.4
  0.4 356.2 142.5   0.4 344.5 137.8
  0.5 318.5 159.2   0.5 308.0 154.0
  0.6 290.6 174.4   0.6 281.0 168.6
  0.7 268.9 188.2   0.7 260.0 182.0
  0.8 251.4 201.1   0.8 243.1 194.5
  0.9 236.9 213.2   0.9 229.1 206.2
  1.0 224.6 224.6   1.0 217.2 217.2

Ahead to Grand Summary of Constraints
Back to Constraints with Θcl = 105°

Back to Intro to Constraints

Back to Physics of the Head Shot