Accession Number : AD0712703


Title :   INVESTIGATION OF THE FEASIBILITY OF MEASURING THE CHAMBER TEMPERATURE OF SOLID PROPELLANT ROCKET MOTORS BY USING MICROWAVE ATTENUATION MEASUREMENTS


Descriptive Note : Technical rept.


Corporate Author : UTAH UNIV SALT LAKE CITY MICROWAVE DEVICE AND PHYSICAL ELECTRONICS LAB


Personal Author(s) : Olsen, R G ; Grow, R W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/712703.pdf


Report Date : Jun 1970


Pagination or Media Count : 69


Abstract : The analysis of a plane wave propagating through a homogeneous plasma region of dimensions large compared to the signal wavelength has shown that the wave attenuation can be related to physical parameters of the plasma such as electron density, temperature, and pressure. In this report, the plasma in the combustion chamber of a small solid propellant rocket motor is used to investigate the feasibility of determining the temperature of the plasma by using microwave attenuation data. Potassium perchlorate is substituted for some of the ammonium perchlorate in the propellant to give an electron density that produces an easily measurable attenuation. The theoretical results show that for a known propellant composition and potassium perchlorate concentration, both the plasma temperature and chamber pressure at equilibrium may be found from one attenuation measurement. Also, for a known thermodynamic state of the plasma, the electron density may be found from the attenuation data. The method of microwave analysis is shown to be very useful in the study of transient phenomena in that no transducers are required; hence, the time response of the measurement is limited only by the microwave detection circuitry. This technique may be used to study localized disturbances within the plasma region.


Descriptors :   *MICROWAVES , *SOLID PROPELLANT ROCKET ENGINES , *SOLID ROCKET PROPELLANTS , MEASUREMENT , EXPERIMENTAL DATA , THERMAL ANALYSIS , COMBUSTION CHAMBERS , ATTENUATION , ELECTROMAGNETIC RADIATION , INTERACTIONS , ELECTRON DENSITY


Subject Categories : Radiofrequency Wave Propagation
      Combustion and Ignition
      Solid Rocket Propellants


Distribution Statement : APPROVED FOR PUBLIC RELEASE