Test Report 3, May 14, 2000

Tri-Mode Launch System
Test Report 3
May 14, 2000

Summary

I'm writing this almost a month after the test. This has given me time to review the problems, causes, and develop corrective actions.

During testing, several problems arose, some were corrected, others were not. Sustained combustion was accomplished, though at much less efficiency than desired. Buzz was encountered during combustion which varied in intensity with fuel flow but not in frequency. Analysis of the testing resulted in several recommendations.

Test Cell


I moved the test setup to the corner of a shed that channeled the wind and increased its speed. On the test day the wind was clipping along at a mild (for desert springtime) 40 mph. This was increased to perhaps 50 as it turned the corner of the shed. The shop-vac added maybe another 20-30 mph.

Test Plan

The goal of this test was:

Engine Construction

..

These pictures show the principle parts and assembly of the Near Flight Weight Engine Number 1 (NFWE-1). It weighs just under 2 lbm and I hope to get about 8 lbf thrust at 120 mph airspeed.

Six parts now make up this engine. The flame holder is flanked by the aft-body and the fore-body. In front are the inlet cone (subsonic) and the two fuel lines.

Fuel Line Mounting

The fuel lines entered the engine aft of the flame holder at a right angle to the aft-body. They then made an s-curve (to avoid pinching) and ran up the inner edge of the flame holder. At the fuel injection end the fuel lines were formed into annular passages. This would allow an accelerator rod to be inserted through the middle without interference.

This method of routing and mounting proved to be very problematic.

Test Results

Conclusions and Recommendations

  1. Some swirl is good, too much is bad.
  2. Better fuel control valves are needed.
  3. Moderation in fuel preheating (or none) is a must.

Future Testing

Note to readers. The onset of spring/summer is causing me to work on other activities that are seasonally sensitive. This means that further testing will be delayed for a while longer.



Page First Created: May 8, 2000
Page Last Updated: May 12, 2000