Untersuchung von Abgasstrahlen aus Kleintriebwerken mit der Lasermesstechnik REMPI

The High Vacuum Test Facility STG enables an experimental investigation of thruster plumes to determine disturbance effects of thruster firing like e.g. perturbing forces and moments, heat loads, and contamination. A large liquid helium-driven cryopump allows the undisturbed plume gas expansion into the highly rarefied regime. The plumes consist of continuum to free molecule flow, and isentropic core/boundary layer expansion into the backflow region. Initially thruster nozzles and sonic orifices are operated with test gases N_2 and H_2 as two essential components of thruster plumes (instead of real propellants such as hydrazine N_2H_4). As a highly sensitive spectroscopic method with short response time 'Resonance Enhanced Multiphoton Ionization' (REMPI) was developed at the STG and put into operation. This technique is applied to determine the thermodynamic variables such as rotational temperature, number density, and flow speed of the molecule N_2 in the different flow types of thruster plumes and orifice flow. (orig.)SIGLEAvailable from TIB Hannover: RN 437(99-27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman