Accession Number : ADA483618


Title :   A Zero Dimensional Time-Dependent Model of High-Pressure Ablative Capillary Discharge (Preprint)


Descriptive Note : Conference paper


Corporate Author : AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE


Personal Author(s) : Pekker, Leonid


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a483618.pdf


Report Date : Jun 2008


Pagination or Media Count : 19


Abstract : A zero-dimensional time-dependent high-pressure slab capillary discharge model is presented. The model includes a heat transfer radiation model based on a radiation database. This database has been constructed using commercially available radiation software PrismSPEC to calculate the radiation heat flux output from an uniform plasma slab. Thus, unlike earlier models, this model does not use any asymptotic radiation models, but self-consistently calculates the radiation heat flux at the thin transition layer, between the uniform plasma core and the ablative capillary walls. The model includes the thermodynamics of partially ionized plasmas and non-ideal effects taking place in the high density plasma and assumes local thermodynamic equilibrium (LTE), fully dissociated plasma, no heat losses into the capillary walls, a ratio of thermal pressure to magnetic pressure much larger than unity and the existence of a sonic condition at the exit plane (the plasma flow is expected to be chocked at the bore exit). The model predicts the existence of two steady-state regimes of plasma pressure for ablative discharge operation at a given plasma temperature. The first regime occurs when the plasma is so dense that the radiation mean free path is less than the slab gap of capillary, the case of super-high pressure capillary discharge. The second regime occurs when the plasma density is much lower such that radiation mean free path is much larger than the capillary gap, i.e. the case of moderately high plasma pressure. Both regimes converge at small plasma temperature, and there is no steady-state solution for small plasma temperatures. Both regimes, radiation and thermal conduction, may be attractive for thruster applications depending on specific configurations.


Descriptors :   *PLASMA ENGINES , MATHEMATICAL MODELS , MAGNETIC FIELDS , SYMPOSIA , NUMERICAL METHODS AND PROCEDURES , EQUATIONS , ENTHALPY , HEAT TRANSFER , IONIZATION


Subject Categories : Plasma Physics and Magnetohydrodynamics
      Thermodynamics
      Electric and Ion Propulsion


Distribution Statement : APPROVED FOR PUBLIC RELEASE