17 research outputs found
Preliminary Design Method of a Turbopump Feed System for Liquid Rocket Engine Expander Cycle
Abstract The present research effort deals with simplified theoretical models for the preliminary design and performances assessment of centrifugal pumps for liquid rocket propulsion. These models have been developed within the Concurrent Design Facility, under development at the Italian Aerospace Research Centre (CIRA), in the framework of the HYPROB program. In particular, this work is aimed at developing a theoretical model, via the implementation of a MatLab code, capable to predict the geometry and performance of centrifugal turbopumps, thus providing useful indications for the preliminary design of the turbopump feed system
Rarefaction Effects in Hypersonic Wind Tunnel in Shock Wave Boundary Layer Interaction Phenomena
DAVID The First 6U Cubesat Mission of the Italian Space Agency Programme Iperdrone as Demonstration of New On Orbit Services Performed by Space Drones
The Italian Space Agency is promoting a roadmap for the design, manufacturing and operation of a new space reentry drone. The Iperdrone program will qualify a new type of operative mission, through an incremental phased approach. The program includes, as first step, the demonstration of inspection services for the International Space Station, optimizing the EVA activities and increasing the in space experimentation opportunities. The paper will present the status of development of the first mission, which will demonstrate the system\u27s capabilities such as proximity operations, inspection and interaction with a target, including a close rendez-vous demonstration. The first mission, DAVID to be launched within 2023, is based on a 6U cubesat architecture
Lunar Gravitational-Wave Antenna
Monitoring of vibrational eigenmodes of an elastic body excited by
gravitational waves was one of the first concepts proposed for the detection of
gravitational waves. At laboratory scale, these experiments became known as
resonant-bar detectors first developed by Joseph Weber in the 1960s. Due to the
dimensions of these bars, the targeted signal frequencies were in the kHz
range. Weber also pointed out that monitoring of vibrations of Earth or Moon
could reveal gravitational waves in the mHz band. His Lunar Surface Gravimeter
experiment deployed on the Moon by the Apollo 17 crew had a technical failure
rendering the data useless. In this article, we revisit the idea and propose a
Lunar Gravitational-Wave Antenna (LGWA). We find that LGWA could become an
important partner observatory for joint observations with the space-borne,
laser-interferometric detector LISA, and at the same time contribute an
independent science case due to LGWA's unique features. Technical challenges
need to be overcome for the deployment of the experiment, and development of
inertial vibration sensor technology lays out a future path for this exciting
detector concept.Comment: 29 pages, 17 figure
Advanced Launcher Technology Maturation Supported by EU-Aeronautic Research Projects
The Aeronautics and Air Transport section of the EU’s FP7 research program includes a topic “Pioneering the air transport of the future” which supports inter alia some high speed aviation concepts. Investigated technologies are similar to advanced space transportation technologies. Two of these currently running FP7 projects with a funding level of several million € each are described in this paper.
The FAST20XX (Future high-Altitude high-Speed Transport 20XX) project is running since the end of 2009 and is managed by ESA-ESTEC. The new project CHATT (Cryogenic Hypersonic Advanced Tank Technologies) is the second project example which is coordinated by DLR-SART.
The paper presents the technologies relevant for future launchers which are maturated within FAST20XX and CHATT. Major research results, as far as available, will be summarized
Hypersonic high altitude aerothermodynamics of a space re-entry vehicle
The analysis of the rarefaction effects in the prediction of the main aerothermal loads of a space re-entry vehicle is presented. It is well known that the Navier–Stokes equations fail in rarefied regimes and therefore other approaches must be used. In the present paper different configurations have been simulated by using the Direct Simulation Monte Carlo method. Moreover, slip flow boundary conditions have been implemented in a Navier–Stokes code in order to extend the validity of such a continuum method in the transitional flow regime. Finally, bridging-formulae for the high altitude aerodynamics of winged bodies have also been used. For the tuning of the methodologies, two simple geometries have been analysed, specifically designed to study the phenomenon of shock wave boundary layer interaction: the first one is a hollow cylinder flare, for which experimental data are also available; the second one is the geometry of a test article that was designed and tested at the Italian Aerospace Research Centre. The other two configurations that have been taken into account are an experimental winged re-entry vehicle and a capsule, for which global aerodynamic coefficients and local wall heating have been determined using different computational approaches. The Navier–Stokes code with slip flow boundary conditions has shown good predictive capabilities of the size of the recirculation bubble compared with the experimental results in the hollow cylinder flare test case; however, for the winged vehicle and capsule case, the CFD results are not fully satisfactory and the Monte Carlo method remains the most reliable approach, together with the bridging formulae, that provide good results for the global aerodynamic coefficients
Validation of conjugate heat transfer model for rocket cooling with supercritical methane
A numerical solver able to describe a rocket engine cooling channel fed with supercritical methane is validated
against experimental data coming from a test article conceived and tested by the Italian Aerospace Research Center.
The multidimensional conjugate heat transfer model numerically solves the Reynolds-averaged Navier–Stokes
equations for the coolant flow and the Fourier’s law of conduction for the heat transfer within the wall. In this study,
an experimental test case is reproduced in detail in order to evaluate the influence of partially unknown parameters,
such as surface roughness and wall thermal conductivity, and of operative parameter uncertainty, such as the coolant
mass flow rate and input heat transfer rate. The comparison made with respect to the wall temperature and coolant
pressure drop of the whole set of experimental data provides complementary information that allows better
understanding of experiments and infers possible deviations from the expected behavior
Mitral Valve Models Reconstructor: a Python based GUI software in a HPC environment for patient-specific FEM structural analysis.
Experimental investigation of transcritical methane flow in rocket engine cooling channel
A test article has been specifically designed in order to investigate the methane behaviour inside rocket engine cooling channels. The test article is composed of a suitable copper-alloy block warmed up by cartridge heaters and of a single channel with rectangular cross section, which is fed with transcritical methane flow. Steady-state conditions and channel dimensions are representative of a typical rocket engine cooling channel. Several tests have been conducted with mass flow rate ranging from 10 to 25 g/s, exit pressure from 60 to 150 bar, and inlet temperature of about 130-140 K. The maximum provided heat flux at channel bottom is 20 MW/m2. Measurements of channel inlet and exit temperature and pressure, mass flow rate, and wall temperature at different channel locations have provided data useful for the evaluation of heat transfer and pressure loss. In particular, the channel surface roughness induced by the manufacturing process has been estimated and a peculiar Nusselt number correlation has been obtained. This correlation is suitable to describe the thermal behaviour of the rectangular cooling channel including both methane flow and wall
Rarefied Aerothermodynamics Technology Development for Future High-Altitude High-Speed Transport (EU-FAST20XX)
First subject of the present paper has been the experimental and numerical characterization of test chamber flow of DLR-V2G low-density wind tunnel, in the frame of EU-FP7 FAST20XX project activities dedicated to the validation of numerical tools able to predict rarefaction effects in suborbital flight. Pitot pressure radial profiles measured at different positions downstream the test chamber have been compared at nozzle exit to numerical results obtained with different methodologies accounting for rarefaction effects (CFD with slip-flow boundary conditions, a hybrid CFD-DSMC procedure), and a re-definition of the V2G facility envelope in terms of flight-relevant parameters (Mach, Reynolds, Knudsen numbers) has been presented. A good agreement between experiments and numerical results has been achieved for M=12 and M=16 cases (not as good for M=22), thus confirming that the test chamber flow knowledge is of fundamental importance for a proper numerical rebuilding of an experimental test campaign. Further, the aerodynamic coefficients of lift, drag and pitching moment of the analyzed lifting body configuration have been experimentally determined by means of three component force and moment measurements in V2G and the influence of rarefaction onto the aerodynamic coefficients have been shown. The results have numerically been validated by means of DSMC calculations. After the validation of the numerical tools, the high altitude effects to the future hypersonic/suborbital re-entry vehicle SpaceLiner have been analyzed. Bridging functions have been developed and validated by means of DSMC calculations. The effects of rarefaction on global longitudinal aerodynamics of SpaceLiner in the range of altitude 65Ă·85 km have been pointed out by comparing to the aerodatabase in continuum regime conditions. DSMC computation has been done in the higher SpaceLiner altitude point confirming the bridging function results and providing heat transfer estimations. Two versions of SpaceLiner have been analyzed: SL4.3 and SL7.1