Review on film cooling of liquid rocket engines

An experimental investigation has been carried out to study the linear-plug-nozzle flowfield development with and without freestream flow. The effect of truncation (40%), plug contour, and side plates on base pressure development has been also studied. Relative to no freestream condition, the higher outward deflection of the initial portion of the free-jet boundary in the presence of freestreamprevents the overexpansion shock from the upper portion of the inner nozzle to impinge on the plug surface, modifying the flow development downstream of the overexpansion shock. This reduces the altitude-adaptive character of the plug nozzle and also influences the base pressure value, which is seen to decrease with increase in freestreamMach number. The nozzle pressure ratio for base wake closure is also found to be sensitive to the plug configuration. Contouring the plug significantly enhances the base pressure value, but a smaller base initiates an early wake closure. The addition of side plates results in an early base wake closure in each case. The characteristic frequency of base pressure fluctuations is found to be strongly dependent on plug configuration and base region size.

Linear-Plug Flowfield and Base Pressure Development in Freestream Flow

Transmission electron microscopy studies of the Pd–C films obtained by physical and chemical vapor deposition

The work toward reusable single-stage-to-orbit launch-vehicle concepts has initiated several research activities
toward a suitable nozzle design, which (unlike bell nozzles) is expected to perform optimally over the entire flight regime. Of these concepts, the annular aerospike nozzle and its variants, linear and truncated, are among the most promising. Given the concern over the intensity of acoustic loading during takeoff, it is vital to carry out a detailed aeroacoustic characterization of aerospike nozzles with special attention to overexpanded conditions, which are
generally encountered during liftoff. In this work, an experimental investigation into aeroacoustics of an annular
aerospike nozzle of design Mach number (Md) of 2.0 has been carried out, and the results are presented. The effect of
truncation of the aerospike to 40 and 60% of the spike length on the acoustic field is also studied and compared with the full-length aerospike. Results show that, in the overexpansion regime, truncated conical aerospike nozzles have reduced acoustic (∼4–5 dB) levels until wake closure compared to the full-length aerospike and conventional
convergent–divergent nozzle, all operating at identical conditions. This noise reduction is predominantly in the region upstream of the nozzle exit. At the peak radiation angle (∼150 deg from the jet upstream direction), the acoustic levels are almost same for all of the nozzles investigated in the present study.

Effect of Spike Truncation on the Acoustic Behavior of Annular Aerospike Nozzles

Dynamic modeling of a 2-dof parallel electrohydraulic-actuated homokinetic platform

A design method for liquid-propellant rocket engines is proposed, on the basis of models adjusted in response to test results. This method increases the reliability of the results and reduces ground testing of the motors. The effectiveness of the method is confirmed by ground testing and flight experience with the motors developed by Salyut Design Bureau at Krunichev State Space-Research Center.

I. S. Partola

Papers

Design of liquid-propellant rocket engines