Thermal Stresses in Hollow Graphite Cylinders with Asymmetric Heating

Abstract

Fig. 3 Typical performance data. rection varies up to 5%. An additional correction, obtained from Ref. 2, for the real gas effects in the flow nozzle is also applied. These corrections have been verified in a series of tests in which the test section was replaced with another criti- cal flow nozzle. With the preceding corrections applied, the two flow rates agree within 1% after the initial starting tran- sient of about 1 sec. Initial tests disclosed a severe ringing of the thrust mea- suring system, i.e., poorly-damped oscillations in response to impulsive thrust forces. This was improved to an accept- able level by means of felt pads isolating the air storage bottles and heat exchanger from the thrust stand bed. Ring- ing time was reduced to about sec. Typical data from two test firings are shown in Fig. 3. Test A-6 illustrates operation at a high air temperature and moderate air flow rate, simulating Mach 3.9 at 20,000 ft alti- tude. Test A-25 shows operation at a high air flow rate (the facility's limit) and a moderate temperature. Conclusions