Download or read book Laser induced Fluorescence Measurements Within an Arcjet Thruster Nozzle written by P. Victor Storm and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Induced Fluorescence of Ground State Hydrogen Atoms in an Arcjet Plume written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report two photon laser induced fluorescence measurements near the nozzle exit and in the plume of a 1 kW arcjet thruster. Atomic hydrogen number densities, axial and radial velocities, and translational temperatures are measured in the expansion plume of a 1 kW arcjet operating on hydrogen propellant. Data from recent computational models are compared with the atomic hydrogen density measurements.
Download or read book Laser induced Fluorescence of Atomic Hydrogen in an Arcjet Thruster written by J. G. Liebeskind and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Optical Diagnostics for Performance Evaluation of Arcjet Thrusters written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser and optical emission-based measurements have been developed and implemented for use on low-power hydrogen arcjet thrusters and xenon-propelled electric thrusters. In the case of low power hydrogen arcjets, these laser induce fluorescence measurements constitute the first complete set of data that characterize the velocity and temperature field of such a device. The research performed under the auspices of this NASA grant includes laser-based measurements of atomic hydrogen velocity and translational temperature, ultraviolet absorption measurements of ground state atomic hydrogen, Raman scattering measurements of the electronic ground state of molecular hydrogen, and optical emission based measurements of electronically excited atomic hydrogen, electron number density, and electron temperature. In addition, we have developed a collisional-radiative model of atomic hydrogen for use in conjunction with magnetohydrodynamic models to predict the plasma radiative spectrum, and near-electrode plasma models to better understand current transfer from the electrodes to the plasma. In the final year of the grant, a new program aimed at developing diagnostics for xenon plasma thrusters was initiated, and results on the use of diode lasers for interrogating Hall accelerator plasmas has been presented at recent conferences. Cappelli, Mark A. Unspecified Center...
Download or read book 32nd AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 1996 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamental Studies of the Electrode Regions in Arcjet Thrusters written by Mark A. Cappelli and published by . This book was released on 1998 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research focuses on the understanding of the plasma dynamics in the near node and near-cathode region of arcjets with an emphasis on the development of an extensive database for the validation of arcjet models. During the first year of this research period, the arc cathode interaction was investigated by in-situ spectroscopic imaging and by axial emission spectroscopy, providing measurements of cathode current density, cathode temperature, and near-cathode plasma properties. In addition, during this grant period, we have extended the use of Laser Induced Fluorescence (LIF) to make measurements of plasma properties within the expanding region of the nozzle and have accumulated an extended data base that includes, in addition to the use of pure hydrogen propellant, mixtures of hydrogen and nitrogen to simulate hydrazine decomposition products. In the final year, a new laser based diastic, Doppler-Free Absorption Spectroscopy (DFAS) was developed and applied to measure the exit plane electron number density in a hydrogen arcjet, one of the last properties needed to provide closure to the vast data set that we have generated for low power hydrogen arcjet. As a spin-off to this grant, the LIF diagnostics that was developed for arcjet through this program was extended to the study xenon plasmas, and implemented to measure both neutral and ionized on velocities at the exit of a Hall thruster. This contributed to a comprehensive study of the near exit region of our Hall discharge device. To compliment the LIF diagnostics on our Hall thrusters, we have made extensive measurements of the transient and time average plasma properties using conventional electrostatic probes.
Download or read book Applied Optics written by and published by . This book was released on 1998 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiphoton Laser Induced Fluorescence for Measuring Point Specific Densities of Ground State Atomic Hydrogen in an Arcjet Plume written by Jeffrey Alan Pobst and published by . This book was released on 1997 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 1996 with total page 1364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Induced Fluorescence Measurements of OMS and LR91 Amine Rocket Exhausts written by C. Brasier and published by . This book was released on 1997 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonintrusive diagnostics are often sought to provide information on combustion exhaust flows due to the harsh environment of the flow. Laser-induced fluorescence (LIF) is one technique in which a chosen flow molecule or marker is probed to yield gross flow properties such as static temperature and flow velocities. The work presented herein describes application of LIF to the combustion exhausts of two full-scale liquid-propellant rocket engines, i.e., the Space Shuttle Orbital Maneuvering System (OMS) and the Titan second-stage LR91 rocket engines, as they undergo routine testing in simulated altitude test cells. The method is based upon the use of CW ring-dye lasers which scan in frequency over either the Na D1 or D2 line at 5896 and 5890 L'. Na is used as a basis for this approach since it occurs as a trace element in both hydrogen and amine rocket fuels. The generic apparatus is described, including a discussion of the collection and interpretation of the LIF signal to yield radial and temporal profiles of radial flow velocity and static temperature. CFD modeling of the plumes was used to provide baseline estimates of the exhaust flow properties. It was found that the CFD model does a fairly good job of predicting the gross behavior of the flow, although some items of fine spatial structure are not reproduced well. The OMS and LR91 rocket engine nozzles are drastically different in construction and cooling method. It was found that excellent LIF results were obtained with the radiation-cooled nozzle (OMS), while the fuel-film cooling (FFC) used for the LR91 nozzle generated an optically thick and particle-laden region which severely impeded the determination of static temperature from the Na LIF measurements. Ancillary optical scattering measurements were made on the LR91 which indicated the existence of an annulus of particles in the flow periphery.
Download or read book 37th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 2001 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demonstration of the Feasibility of Laser Induced Fluorescence for Arc Jet Flow Diagnostics written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser Induced Fluorescence (LIF) studies are carried out on nitric oxide and oxygen molecules in the arc jet flows at the NASA Johnson Space Center Reentry Testing Facility. Measurements are taken in the free stream and from a blunt body shock layer. Tests are performed under different flow conditions to determine the feasibility and sensitivity of the LIF technique for various species. This is developed as a part of high enthalpy flow diagnostics and will be useful to elucidate the rotational and vibrational temperatures. Adequate sensitivity for the detection of O(2) and NO is demonstrated. Proposed improvements of the existing system are presented. Arepalli, Sivaram Unspecified Center NAS9-17900...
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Induced Fluorescence Measurements Within a Laboratory Hall Thruster Postprint written by and published by . This book was released on 1999 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we describe the results of a study of laser induced fluorescence velocimetry of ionic xenon in the plume and interior acceleration channel of a laboratory Hall type thruster operating at powers ranging from 250 to 725 W. Optical access to the interior of the Hall thruster is provided by a 1 mm axial slot in the insulator outer wall. Axial ion velocity profiles for four discharge voltages (100 V, 160 V, 200 V, 250 V) are measured as are radial velocity profiles in the near field plume. Internal neutral xenon axial velocity profiles are also measured at these conditions. For each test condition, the implied axial electric field is calculated from the measured ionic velocity profiles. These results are compared to previous plasma potential measurements performed with an emissive probe. The correspondence between the two sets of measurements indicates that the ionization and acceleration regions within the thruster are separated to some degree.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 34th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 1998 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:
