Conditions for Choking in a Cylindrical Combustion Chamber with Eddying Pressure Losses

Citation

Browning, Frank Horace and Mcconnaughhay, ]ames William (1946) Conditions for Choking in a Cylindrical Combustion Chamber with Eddying Pressure Losses. Engineer's thesis, California Institute of Technology. doi:10.7907/BC2C-0A22. https://resolver.caltech.edu/CaltechETD:etd-12112008-111809

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Choking occurs in a cylindrical combustion chamber when the gas reaches sonic velocity at the outlet, and no more fuel can be burned without causing unstable combustion and possibly "blowout" of the flame. In this analysis, the conditions for choking and the maximum possible fuel-air ratio for given inlet conditions are determined by a trial and error method, which proves to give accuracy within about 1/2 percent. Entering Fig. 13, 14, or 15 with the given inlet conditions, the fuel- air ratio for choking [(...)] is determined. From Fig. 16, 17, or 18, the temperature of the gas at the outlet is determined. Then [...] can be found from Fig. 1, 2, or 3, and the pressure and density of the gas at the outlet from equations (12) and (13). If [...] is assumed to remain constant over the temperature range involved, and constant with respect to change in the gas composition due to combustion, then it is possible to solve algebraicly for the conditions for choking. This approximation is reasonably valid for small fuel-air ratios, but may cause errors of over ten percent when the inlet temperature is low and the fuel-air ratio is high.

Thesis Files