| OCR Text |
Show 21 of oscillations and the wavelength is given from acoustical theory (29) as 'Ai (1) c = g whee 'A is the c g wavelength is the velocity of axial mode frequency is twice ,of the standing wave, sound in the the length The gas. of the gas is its f wavelength frequency and of the first chamber and thus its is c f = __6_ (2) 2L g where L is the should thus be of length g the gas column. straight line with a that the observed frequencies are a speed of sound slope of rather well in the burner which is oontains the data from which Figure 6 c 12. llL against g Figure 6 shows g explained by this rela- 2,680 was feet per second. Table 1 determined and is located in D. Appendix cies of f plot The slope of the line in Figure 6 is used to determine the tionship. In A Figure 6 the drift is due to probably of the conditions in the cold-gas section. section is made longer, clearly becomes lower due to the Consequently, cold section as section is thus hot throughout use of an length greater more reduced is temperature in penetration by the inoreased. than it would be entire chamber. equivalent progressivley the average gas the hot As this cold end gases. velocity of sound becomes progressively less its the points below the line at low frequen- total in the The effective length of the if the gases were uniformly Correction for this effect by the length should shift the low frequency points to the left and thus reduce the above drift. A |
