another batch
authorBdale Garbee <bdale@gag.com>
Thu, 1 Jun 2017 06:14:43 +0000 (00:14 -0600)
committerBdale Garbee <bdale@gag.com>
Thu, 1 Jun 2017 06:14:43 +0000 (00:14 -0600)
rockets/research/2017-batch-03.mdwn
rockets/research/2017-batch-04.mdwn [new file with mode: 0755]

index 200bd2e..096f6bf 100755 (executable)
@@ -25,13 +25,27 @@ Simulation says:
 
 Average casting tube mass 1.13g.
 
-* Grain 1, ?g gross, ?g net
-* Grain 2, ?g gross, ?g net
-* Grain 3, ?g gross, ?g net
-* Grain 4, ?g gross, ?g net
-* Grain 5, ?g gross, ?g net
-* Grain 6, ?g gross, ?g net
-
-With a 10.00" liner, 14/64" nozzle throat, buna-n o-rings, simulation says
-this makes a 37% H-156, 208 Ns, with about a 1.2 sec burn.
+Coring rods extracted easily, new hickory tube caps came off without too
+much effort.  Slight cleanup at the top of each grain since propellant always
+seems to fillet around the coring rod.  Grain average fill levels looks pretty
+good, with on the order of 1mm space at the top as expected.
+
+* Grain 1, 26.57g gross, 25.44g net
+* Grain 2, 26.63g gross, 25.50g net
+* Grain 3, 26.65g gross, 25.52g net
+* Grain 4, 26.01g gross, 24.88g net (visible undefill)
+* Grain 5, 26.51g gross, 25.38g net
+* Grain 6, 26.75g gross, 25.62g net
+
+Total of 152.34g propellant, vs 159g simulated.
+
+Note that after casting grains and cutting a liner to 10.0", I realized I'd
+mis-measured the case, and we actually had 10.4" of liner/propellant length
+to play with!  Fix this for the next time we make grains...  For now, we'll
+fly these grains in a correct length liner and live with the fact that we 
+could have put another 0.4" of propellant in the case!  That'd be another
+13 Ns according to the simulator...
+
+With a 10.40" liner, 14/64" nozzle throat, buna-n o-rings, simulation says
+this reload will be a 37% H-155, 208 Ns, with about a 1.2 sec burn.
 
diff --git a/rockets/research/2017-batch-04.mdwn b/rockets/research/2017-batch-04.mdwn
new file mode 100755 (executable)
index 0000000..a0e376f
--- /dev/null
@@ -0,0 +1,40 @@
+# Batch 2017-batch-04 #
+
+4 grains of 29mm using sorbitol, intended to be a reloads for the 
+second-longest GMA 29mm snap-ring case.  Grain length 45mm with 1mm spacing 
+per grain, so we'll make the casting tubes 46mm long.  Delrin coring rods of 
+5/16" diameter.  
+
+Formula for a batch size of 135g:
+
+* 65% KNO3, 87.75g, taken from the big bucket
+* 35% Sorbitol, 47.25g
+* 1% RIO, 1.35g
+* PolyStep B1, 2 drops
+
+Presto Multicooker operated at 275F indicated.
+
+These grains were cast on 1 June 2017.
+
+Simulation says:
+
+<p>
+<!--Begin motor 29mm 4-grain Sorbitol #14 HTML export from MotorSim-->
+<table class='motor' style='text-align: left; border: 1px solid black'><tr><th colspan='6' class='title'>29mm 4-grain Sorbitol #14</th></tr><tr class='summary'><th>Rating:</th><td>99% G-180</td><th>Max Pressure:</th><td>6.47 MPa (939 psi)</td></tr><tr class='summary'><th>Total Impulse:</th><td>159 Ns</td><th>Specific Impulse:</th><td>133 s</td></tr><tr class='summary'><th>Max Thrust:</th><td>228 N</td><th>Volume Loading:</th><td>69%</td></tr><tr class='summary'><th>Average Thrust:</th><td>180 N</td><th>Fuel Mass:</th><td>122 g</td></tr><tr><td colspan='4' class='thrust'><img src='http://chart.apis.google.com/chart?chxt=x,x,y,y,r,r&chs=400x200&cht=lxy&chco=3072F3&chds=0,0.89,0,227.96&chxr=0,0,0.89|2,0,227.96|4,0,51.25&chd=t:0,0,0,0,0,0,0,0,0,0,0.02,0.04,0.07,0.12,0.19,0.29,0.44,0.52,0.65,0.78,0.8,0.88,0.89|0,10.15,19.94,29.95,39.31,47.83,55.66,62.85,69.45,75.47,134.47,149.05,157.98,170.21,186.92,207.36,225.35,227.96,219.77,198.86,37.95,0.12,0.06&chxl=1:|s|3:|N|5:|lbf&chxp=1,50|3,50|5,50' width='400' height='200' alt='null' /></td></tr></table>
+<!--End motor 29mm 4-grain Sorbitol #14-->
+</p>
+
+## Results ##
+
+Average casting tube mass 1.25g.
+
+* Grain 1, ?g gross, ?g net
+* Grain 2, ?g gross, ?g net
+* Grain 3, ?g gross, ?g net
+* Grain 4, ?g gross, ?g net
+
+Total of ?g propellant, vs 122g simulated.
+
+With a 7.40" liner, 14/64" nozzle throat, buna-n o-rings, simulation says
+this reload will be a 99% G-180, 159 Ns, with about an 0.8 sec burn.
+