STABILITY OF FILTRATION COMBUSTION IN A CYLINDRICAL RADIATION HEATER WITH A POROUS WORKING MEDIUM K. V. Dobrego , S. A. Zhdanok , A. V. Krauklis , E. I. Khanevich , A. I. Zaruba , D. V. Sakhnovich , and A. N. Ovcharenko UDC 536.46 Special features of the localization of a combustion front in a cylindrical radiation heater with a porous working medium, for which use was made of charges of aluminar, magnesite sand, and expanded clay aggregate with different grain sizes, are studied experimentally. A qualitative analysis of thermohydrodynamic instability of filtration combustion (FC) is made, based on which the existence of a critical radius of localization of the combustion front in the cylindrical burner is established. A qualitative agreement between analysis and experiment in filtration from the center to the periphery is shown. JEPTER7492019998 JEPTER749208