TY - JOUR
T1 - Influence of relaxation processes on the structure of a thermal boundary layer in partially ionized argon
AU - van Dongen, M.E.H.
AU - van Eck, R.B.P.
AU - Hagebeuk, H.J.L.
AU - Hirschberg, Avraham
AU - Hutten-Mansfeld, A.C.B.
AU - Jager, H.J.
AU - Willems, Jan F.H.
PY - 1981/1/1
Y1 - 1981/1/1
N2 - A model for the unsteady thermal boundary-layer development at the end wall of a shock tube, in partially ionized atmospheric argon, is proposed. Consideration is given to ionization and thermal relaxation processes. In order to obtain some insight into the influence of the relaxation processes on the structure of the boundary layer, a study of the frozen and equilibrium limits has been carried out. The transition from a near-equilibrium situation in the outer part of the boundary layer towards a frozen situation near the wall has been determined numerically. Experimental data on the electron and atom density profiles obtained from laser schlieren and absorption measurements are presented. A quantitative agreement between theory and experiment is found for a moderate degree of ionization (3 %). At a higher degree of ionization the structure of the boundary layer is dominated by the influence of radiation cooling, which has been neglected in the model.
AB - A model for the unsteady thermal boundary-layer development at the end wall of a shock tube, in partially ionized atmospheric argon, is proposed. Consideration is given to ionization and thermal relaxation processes. In order to obtain some insight into the influence of the relaxation processes on the structure of the boundary layer, a study of the frozen and equilibrium limits has been carried out. The transition from a near-equilibrium situation in the outer part of the boundary layer towards a frozen situation near the wall has been determined numerically. Experimental data on the electron and atom density profiles obtained from laser schlieren and absorption measurements are presented. A quantitative agreement between theory and experiment is found for a moderate degree of ionization (3 %). At a higher degree of ionization the structure of the boundary layer is dominated by the influence of radiation cooling, which has been neglected in the model.
UR - http://www.scopus.com/inward/record.url?scp=0019598012&partnerID=8YFLogxK
U2 - 10.1017/S002237780001059X
DO - 10.1017/S002237780001059X
M3 - Article
AN - SCOPUS:0019598012
SN - 0022-3778
VL - 26
SP - 147
EP - 175
JO - Journal of Plasma Physics
JF - Journal of Plasma Physics
IS - 1
ER -