Rocket engine plume diagnostics using video digitization and image processing - Analysis of start-up

1991 ◽  
Author(s):  
P. DISIMILE ◽  
B. SHOE ◽  
A. DHAWAN
Keyword(s):  
Image Processing ◽  
Rocket Engine ◽  
Start Up ◽  
Video Digitization

scholarly journals X-Ray Measurements in a Cavitating Centrifugal Pump During Fast Start-Ups

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
S. Duplaa ◽  
O. Coutier-Delgosha ◽  
A. Dazin ◽  
G. Bois
Keyword(s):  
Centrifugal Pump ◽  
Rocket Engine ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Centrifugal Impeller ◽  
X Ray ◽  
Speed Increase ◽  
Start Up ◽  
Fast Start ◽  
Start Ups

The start-up of rocket engine turbopumps is generally performed in a few seconds or even less. It implies that these pumps reach their nominal operating conditions after a few rotations only. During the start-up, the flow evolution within the pump is governed by transient phenomena, based mainly on the flow rate and rotation speed increase. Significant pressure fluctuations, which may result in the development of cavitation, are observed. A centrifugal impeller whose transient behavior during start-ups has been detailed in a previous publication is considered. Three different cases of fast start-ups have been identified according the final operating point (Duplaa et al., 2010, “Experimental Study of a Cavitating Centrifugal Pump During Fast Start-Ups,” ASME J. Fluids Eng., 132(2), p. 021301). The aim of this paper is to analyze the evolution during the start-ups of the local amount of vapor in the blade to blade channels of the pump by fast X-ray imaging. This technique has enabled to calculate the time-evolution of the fluid density within the pump, which appears to be correlated with pressure time-evolutions. For each investigated start-up, X-ray measurements have been performed at three different sections of the impeller height. For each investigated start-up and section tested, measurements have been performed for several initial positions of the impeller, to estimate the measurement uncertainty, and to obtain records from different beam angles, like in tomography.

scholarly journals Burn Time Correction of Start-Up Transients for CAMUI Type Hybrid Rocket Engine

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 385
Author(s):  
Tor Viscor ◽  
Hikaru Isochi ◽  
Naoto Adachi ◽  
Harunori Nagata
Keyword(s):  
Rocket Engine ◽  
State Level ◽  
Impinging Jet ◽  
Rocket Engines ◽  
Transient Effects ◽  
Hybrid Rocket ◽  
Start Up ◽  
Time Correction ◽  
Hybrid Rocket Engine ◽  
Time Issue

Burn time errors caused by various start-up transient effects have a significant influence on the regression modelling of hybrid rockets. Their influence is especially pronounced in the simulation model of the Cascaded Multi Impinging Jet (CAMUI) hybrid rocket engine. This paper analyses these transient burn time errors and their effect on the regression simulations for short burn time engines. To address these errors, the equivalent burn time is introduced and is defined as the time the engine would burn if it were burning at its steady-state level throughout the burn time to achieve the measured total impulse. The accuracy of the regression simulation with and without the use of equivalent burn time is then finally compared. Equivalent burn time is shown to address the burn time issue successfully for port regression and, therefore, also for other types of cylindrical port hybrid rocket engines. For the CAMUI-specific impinging jet fore-end and back-end surfaces, though, the results are inconclusive.

Pressure Surge During Cryogenic Feedline Chilldown Process

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Gagan Agrawal ◽  
S. Sunil Kumar ◽  
Deepak Kumar Agarwal
Keyword(s):  
Numerical Study ◽  
Rocket Engine ◽  
Inlet Pressure ◽  
Working Fluid ◽  
Flash Evaporation ◽  
Two Phase ◽  
Numerical Studies ◽  
Start Up ◽  
Flow Through ◽  
Pressure Surge

Cryogenic fluid entering a warm feedline absorbs heat and undergoes rapid flash evaporation leading to pressure surges, which can retard the flow inside the feedline. It may have serious repercussion in operation of the rocket engine during start up. Experimental and numerical studies are carried out to examine the effect of inlet pressure and initial feedline temperature on pressure surges. An analytical model using sinda/fluint software is developed to investigate this complex two-phase flow phenomenon including the various boiling regimes that exist during line chilling. The numerical study is carried out considering 1D flow through a cryogenic feedline of 2.47 m long and 0.01 m inner diameter with liquid nitrogen at 77.3 K as working fluid. Predictions are made for the inlet pressure in the range of 0.28–0.76 MPa and initial wall temperature of 200 K and 300 K. Subsequently, an experimental test rig is setup and the model is validated with the experimental data. The studies show that within the range of parameter considered, the magnitude of pressure surge increases exponentially with increase in inlet pressure and decreases with the prechilling of feedline.

scholarly journals Fluid–structure interaction study of the start-up of a rocket engine nozzle

2010 ◽  
Vol 39 (7) ◽  
pp. 1208-1218 ◽  
Author(s):  
Luciano Garelli ◽  
Rodrigo R. Paz ◽  
Mario A. Storti
Keyword(s):  
Rocket Engine ◽  
Fluid Structure Interaction ◽  
Interaction Study ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Start Up

A 1-D Start-up Analysis for Liquid Rocket Engine Powerpacks

2019 ◽  
Vol 24 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Seongha Yu ◽  
Seongha Yu ◽  
Hongjip Kim ◽  
Seong-Lyong Kim
Keyword(s):  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Start Up ◽  
Liquid Rocket

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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