Searched for: subject:"nozzle"
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Azzini, L. (author), Pini, M. (author), Colonna di Paliano, Piero (author)
An investigation on non-equilibrium condensing steam flow is conducted to attain a semi-analytical model for the prediction of the Wilson point up to the critical point. The database for the analysis includes experimental observations in various nozzles and conditions (ranging from 20 to 150 bar) taken from the literature as well as additional...
journal article 2018
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Romanelli, G (author), Mignone, Andrea (author), Cervone, A. (author)
Pulsed fusion propulsion might finally revolutionise manned space exploration by providing an affordable and relatively fast access to interplanetary destinations. However, such systems are still in an early development phase and one of the key areas requiring further investigations is the operation of the magnetic nozzle, the device meant to...
journal article 2017
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Örley, F. (author), Trummler, T. (author), Hickel, S. (author), Mihatsch, M.S. (author), Schmidt, S.J. (author), Adams, N.A. (author)
We employ a barotropic two-phase/two-fluid model to study the primary break-up of cavitating liquid jets emanating from a rectangular nozzle, which resembles a high aspect-ratio slot flow. All components (i.e., gas, liquid, and vapor) are represented by a homogeneous mixture approach. The cavitating fluid model is based on a thermodynamic...
journal article 2015
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Agostinho, L.L.F. (author), Yurteri, C.U. (author), Wartena, J. (author), Brouwer, S.P. (author), Fuchs, E.C. (author), Marijnissen, J.C.M. (author)
In this study, a multinozzle electrohydrodynamic atomization device was designed and studied for electrosprays in the simple-jet mode. Results have shown that the proposed device produces droplets with similar diameter in all nozzles, that the electric field creates a unique dispersion of the charged droplets and that it can operate under...
journal article 2013
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Vuorinen, V. (author), Yu, J. (author), Tirunagari, S. (author), Kaario, O. (author), Larmi, M. (author), Duwig, C. (author), Boersma, B.J. (author)
Large-eddy simulations (LES) based on scale-selective implicit filtering are carried out in order to study the effect of nozzle pressure ratios on the characteristics of highly underexpanded jets. Pressure ratios ranging from 4.5 to 8.5 with Reynolds numbers of the order 75?000–140?000 are considered. The studied configuration agrees well with...
journal article 2013
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La Torre, F. (author)
A new satellite philosophy, developed during the last two decades, suggests to make satellites smaller and lighter rather than bigger and heavier. In other words, large (?m3), single system satellites are being replaced by ?eets of small (?dm3), so-called micro-satellites. Future developmentsmay result in swarms ofmicro satellites ?ying through...
doctoral thesis 2011
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Migliaccio, A. (author), Zandbergen, B.T.C. (author), Nardini, F.T. (author), Louwerse, M.C. (author)
The number of micro and nano satellite projects is expanding. Main focus is on providing these small satellites with the same capabilities as today's larger satellites. In the field of propulsion, efforts are on miniaturization of the on-board propulsion system. This though presents major challenges to the designers. TNO Defence, Security and...
conference paper 2010
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Stachewicz, U. (author), Yurteri, C.U. (author), Marijnissen, J.C.M. (author), Dijksman, J.F. (author)
This study demonstrates that the hydrodynamic phenomena taking place inside the capillary limits the frequency range of voltage pulses for stable single event electrospraying (SEE), when the meniscus/cone size is defined by the inner diameter of the nozzle. For the analysis of SEE, we used a one-dimensional model describing the displacement and...
journal article 2009
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Odenthal, H.J. (author), Falkenreck, U. (author), Schlüter, J. (author)
The three-dimensional, transient, non-isothermal flow of melt, slag and oxygen/argon is simulated for a 335 t combined blowing converter with six-hole top lance and 14 bottom tuyeres. The calculation is based on the Reynolds averaged Navier-Stokes (RANS) equations and the Standard k-epsilon model. The time-dependent formation of the melt...
conference paper 2006
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Veryovkin, A.A. (author), Tsirkunov, Y.M. (author)
The paper describes the results of computational simulation of an unsteady two-phase gas-particle flow in a hypersonic shock tunnel. The tunnel consists of a heated shock tube, a convergent-divergent nozzle linked up with the low-pressure chamber of the tube, a test section where a model is placed, and a exhaust chamber. In calculations, the...
conference paper 2006
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Arian, M. (author), Tahsini, A.M. (author)
Pulse detonation engine is a new concept across air-birthing propulsion systems. Today, due to the unsteady behavior of this type of engine, design optimizations are not completed yet. In this regard, recent studies are focused on the effects of nozzle implementation in this propulsion system. In this paper, the effect of nozzle shape (angle &...
conference paper 2006
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Khan, I.M. (author), Gilbert, T. (author), Barigou, M. (author)
The shape of the nozzle geometry is increasingly attractive in heating, ventilation and air conditioning applications. However an important consideration in the design of nozzle geometry is its effect on the dynamics of near flow field jet and to minimise the manufacturing cost for practical applications. In this investigation the effect of an...
conference paper 2006
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Naghib-Lahouti, A. (author), Tolouei, E. (author)
Aerospike nozzles are known to produce more thrust than conventional convergent-divergent nozzles in off-design conditions because of their capability to adapt their boundaries to ambient conditions. However, the central plug of an ideal aerospike nozzle can be very long and heavy, and its sharp end is susceptible to deformation in high...
conference paper 2006
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González, B. (author), Galván, B. (author), Winter, G. (author)
Our methodology is to use evolutionary algorithms (EAs) as a simulation and meshless method, because of the equivalence between verifying a numerical scheme for a nodal point and minimizing a corresponding objective function at this point. One advantage and powerful characteristic of our methodology is that mathematical knowledge and theories...
conference paper 2006
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Schmidt, S.J. (author), Sezal, I.H. (author), Schnerr, G.H. (author)
The present paper focuses on a numerical approach based on the Riemann problem to simulate liquid flows with phase changes. Thereby, the flow properties include velocities from O(1) m/s to O(100) m/s and pressures from p approx 0 bar to O(1000) bar. The thermal and caloric behavior of liquid and vapor will be described by suitable equations of...
conference paper 2006
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Turunen-Saaresti, T. (author), Tang, J. (author), Larjola, J. (author)
Polynomial functions are generated to describe real gas properties in computational fluid dynamics (CFD). Two-variable relative least square fitting is applied. In this way the real gas model can be generated fast and easily and the computational time requested is small and precision of the function can be easily adjusted. In this paper this...
conference paper 2006
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Wisse, M.E.N. (author)
The major technical challenge the development of next-generation launchers is facing today, is to achieve complete reusability in two stages to orbit or ultimately in one single stage. These Two-Stage-To-Orbit (TSTO) or Single-Stage-To-Orbit (SSTO) Reusable Launch Vehicles (RLV) may reduce payload cost by a factor of ten or more. The challenge,...
doctoral thesis 2005
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Hagmeijer, R. (author)
Computational grids are used for the discretisation of partial differential equations (PDE's) such that solution of the resulting system of algebraic equations for the discrete values of the dependent variables provides an approximation to the solution of the system of PDE's. When the discretisation of the partial differential equations (PDE's)...
report 1997
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Spekreijse, S.P. (author), Venis, A.C.J. (author)
An efficient Roe-type flux-difference scheme for chemically reacting inviscid compressible flow in thermal equilibrium is presented. The numerical scheme is validated. Three well known chemical models are compared. The set of testcases concerned quasi one-dimensional hypersonic nozzle flows, with and without strong normal Shockwaves.
report 1990
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de Wolf, W.B. (author), Munniksma, B. (author)
An experimental investigation was carried out concerning the effect of jet heating and external flow on the mean flow properties of a subsonic jet. A 60 mm diameter jet was tested in a wind tunnel at wind speeds of 0 and 60 m/s. Jet mach numbers varied between O.44 and 0.94 and jet total temperatures were 310 and 86O K. Velocity and temperature...
report 1980
Searched for: subject:"nozzle"
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