SHOCK WAVES STUDIES USING A PLASMA WIND TUNNEL.
Abstract
A plasma wind tunnel was constructed with the goal of producing a collision free fully ionized stream of hydrogen in which stationary collision free shocks can be produced. Such a flow was produced with a magnetic field buried in the flow with components both perpendicular and parallel to the flow direction. Stationary shock waves were created in this flow by placing a magnetic dipole in the flow with its axis parallel to the flow direction. The flow geometry was studied using magnetic and electric probes, along with photographs of the flow. The structure of shock waves in fully ionized hydrogen flow was studied, and the thickness of the shock waves is equal to several ion gyro radii when the Alfven Mach number of the flow is between 2 and 3 and the angle of the B field with respect to the flow direction is between 45 degrees and 80 degrees. Furthermore, oscillations in the B and E fields are seen to stand ahead of the main shock jump with frequencies larger than the ion gyro frequency. A crude estimate of the dissipation due to these oscillations upon the ionized flow in the shock indicates that these standing magnetohydrodynamic waves may account for the dissipation required for the shock jump conditions when the Alfven Mach number is between 1.5 and 3. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0824378
Entities
People
- E. R. Pugh
- R. M. Patrick