Arcjet rocket

About: Arcjet rocket is a research topic. Over the lifetime, 1121 publications have been published within this topic receiving 9687 citations. The topic is also known as: Arcjet.

Thrust termination dynamics of solid propellant rocket motors

Abstract: A CTIVE thrust termination or reversing of a separatingmotor are ways to facilitate the staging process and improve the performance of a multistage rocket [1–4]. This is done by opening a secondary nozzle located on the motor head and causing rapid depressurization of the motor chamber. During a rapid change in the chamber pressure the burning rate becomes a nonlinear function of pressure and its time rate of change. The strong dependence of the solid propellant burning rate on the chamber pressure results in a transient nonlinear behavior that may cause premature dynamic extinguishment of the motor. Solid propellants’ transient burning and extinguishment during rapid pressure change have been the subject of a number of studies and several transient burning models have been developed [5–8]. Zeldovich has proposed a comprehensive model based on the unsteady rate of heat transfer to the propellant surface and the time rate of change of the temperature distribution in the solid propellant [6]. This model requires specification of many experimentally determined parameters. The transient burning rate model proposed by Von Elbe and McHale is easy to implement and requires instantaneous pressure and its time rate of change for the regression rate prediction [5]. References [1,2] studying motor transient behavior have used a control volume approach for the gas dynamic simulation of the motor’s internal ballistics. However during the active thrust termination (or reversing) process there is a considerable pressure variation along the motor port and there is a rapid propagation of expansionwaves, through the thrust termination nozzles. These expansion waves play an important role in the transient thrust behavior and a more comprehensive flow model should be used for the internal ballistics’ simulation.

Interior plasma diagnostics of arcjet thrusters

Abstract: We review past experimental measurements of internal flow properties of arcjet thrusters. These measurements are generally classified as either intrusive, requiring design changes to prototype thrusters, or nonintrusive, and include measurements of cathode temperature, as well as static pressure, flow temperatures (vibrational, rotational, electronic, translational), electron density, and velocity throughout the interior region extending to the exit plane. Comparisons are made to available model predictions. These measurements, performed on a wide range of thrusters, and operating on variety of propellants, indicate that the nozzle plasma flow may be removed from local thermodynamic equilibrium.

Arcjet Testing and Thermal Model Development for Multilayer Felt Reusable Surface Insulation

Abstract: Felt reusable surface insulation was used extensively on leeward external surfaces of the shuttle Orbiter, where the material is reusable for temperatures up to 670 K. For application on leeward surfaces of the Orion multipurpose crew vehicle, where predicted temperatures reach 1620 K, the material functions as a pyrolyzing conformable ablator. An arcjet test series was conducted to assess the performance of multilayer felt reusable surface insulation at high temperatures, and a thermal-response, pyrolysis, and ablation model was developed. Model predictions compare favorably with the arcjet test data.

The 10 kW power electronics for hydrogen arcjets

Abstract: A combination of emerging mission considerations such as 'launch on schedule', resource limitations, and the development of higher power spacecraft busses has resulted in renewed interest in high power hydrogen arcjet systems with specific impulses greater than 1000 s for Earth-space orbit transfer and maneuver applications. Solar electric propulsion systems with about 10 kW of power appear to offer payload benefits at acceptable trip times. This work outlines the design and development of 10 kW hydrogen arcjet power electronics and results of arcjet integration testing. The power electronics incorporated a full bridge switching topology similar to that employed in state of the art 5 kW power electronics, and the output filter included an output current averaging inductor with an integral pulse generation winding for arcjet ignition. Phase shifted, pulse width modulation with current mode control was used to regulate the current delivered to arcjet, and a low inductance power stage minimized switching transients. Hybrid power Metal Oxide Semiconductor Field Effect Transistors were used to minimize conduction losses. Switching losses were minimized using a fast response, optically isolated, totem-pole gate drive circuit. The input bus voltage for the unit was 150 V, with a maximum output voltage of 225 V. The switching frequency of 20 kHz was a compromise between mass savings and higher efficiency. Power conversion efficiencies in excess of 0.94 were demonstrated, along with steady state load current regulation of 1 percent. The power electronics were successfully integrated with a 10 kW laboratory hydrogen arcjet, and reliable, nondestructive starts and transitions to steady state operation were demonstrated. The estimated specific mass for a flight packaged unit was 2 kg/kW.