Search results for "Fluid dynamic"
showing 10 items of 1034 documents
A Numerical Approach to the Keel Design of a Sailing Yacht
2008
This paper describes an approach to the keel design of a sailing yacht. The related software, which is fully automatic, permits to obtain an optimal shape by modifying the surface used to define the keel planform. B-spline curves and surfaces have been used because of their ability in following complex shapes. The algorithm integrates ad hoc implemented original software with Computational Fluid Dynamics (CFD) commercial ones. The optimisation procedure makes use of Genetic Algorithms (GAs) and a gradient – based optimiser for the refinement of the solution. A careful CAD and CFD modelling leads to a stable and efficient generalised method, which has been applied to the design of the centre…
Modelling nanoscale fluid dynamics and transport in physiological flows
1996
The concept of nanotechnology is discussed, and its connection with biomedical engineering is elucidated. For the specific field of nanoscale flow and transport problems of physiological relevance, some typical examples are presented, and their interaction is discussed for some classic biomechanical problems like the flow in arteries with blood-wall coupling. Then, existing computational models are presented and classified according to the length scale of interest, with emphasis on particle-fluid problems. Final remarks address the essential unity of biomedical and engineering behaviour and the possible relevance to small-scale industrial research.
FE Calculation Methodology for the Thermodynamic Fatigue Analysis of an Engine Component
2006
Thermo mechanical fatigue problem is treated to define an analysis methodology permitting the strength evaluation by reliability viewpoint. The main difficulty is the lack of both theoretical and experimental information; consequently the problem is treated verifying continually the validity and the limits of the developing solution method. The main task of the activity described in this paper was the development of a numerical methodology, based on FE analyses, for the evaluation of the structural behavior of engine components subjected to thermo mechanical fatigue phenomena. The chosen application was the exhaust manifold of an IC engine; FE analyses were executed following the standard m…
Numerical studies of the melting process in the induction furnace with cold crucible
2008
PurposeAims to present recent activities in numerical modeling of cold crucible melting process.Design/methodology/approach3D numerical analysis was used for electromagnetic problem and 3D large eddy simulation (LES) method was applied for fluid flow modeling.FindingsThe comparative modeling shows, that higher H/D ratio of the melt is more efficient when total power consumption is considered, but this advantage is held back by higher heat losses through the crucible walls. Also, calculations reveal that lower frequencies, which are energetically less effective, provide better mixing of the melt.Originality/value3D electromagnetic model, which allows to take into account non‐symmetrical dist…
Comparison between laboratory and pilot biotrickling filtration of air emissions from painting and wood finishing
2010
BACKGROUND: Painting and wood finishing is one industrial sector affected by the European Union environmental regulations on volatile organic compound (VOC) air emissions. The painting process typically results in high flow rates with low VOC concentrations, so biotrickling filtration could be an economical alternative for controlling air emissions. This study analyses the operation of a pilot unit installed in a furniture facility, and compares its performance with the removal efficiency obtained in the laboratory using a synthetic feed composed of n-butyl acetate, toluene and m-xylene to simulate industrial air emissions. RESULTS: Laboratory studies showed that fluctuating and oscillating…
Experimental and Numerical Analysis of a Cross-Flow Turbine
2016
An important component of the management cost of aqueducts is the energy costs. Part of these costs can be recovered by transforming some of the many existing energy dissipations into electric energy by means of economical turbines. This paper describes an experimental study that has been carried out in order to (1) test the performance of an economical cross-flow turbine that maintains high efficiency within a large range of water discharges, and (2) validate a new approximate formula relating main inlet velocity to inlet pressure. It is demonstrated that the proposed formula, on the basis of some simplifying assumptions, exactly links inlet velocity to inlet pressure with any possible geo…
MORPHODYNAMIC PROCESSES DOWNSTREAM OF MAN-MADE STRUCTURAL INTERVENTIONS: experimental investigation of the role of turbulent flow structures in the p…
2012
Abstract Experimental program was conducted to analyze scour – caused by a horizontal jet downstream of a rigid bed – and the flow velocity and turbulence characteristics within the scour hole. The experimental program was motivated by the fact that the knowledge of flow field, including turbulent characteristics, is fundamental to correctly simulate the bed-load transport and the temporal evolution of the scour hole and, thus, to define protective measures of scouring. In this paper some results of experiments – carried out to understand the role of flow turbulence in the prediction of scouring process and sediment movement – are reported. The analysis is conducted on the basis of detailed…
Performance of a pilot-scale biotrickling filter in controlling the volatile organic compound emissions in a furniture manufacturing facility.
2009
A 0.75-m3 pilot-scale biotrickling filter was run for over 1 yr in a Spanish furniture company to evaluate its performance in the removal of volatile organic compounds (VOCs) contained in the emission of two different paint spray booths. The first one was an open front booth used to manually paint furniture, and the second focus was an automatically operated closed booth operated to paint pieces of furniture. In both cases, the VOC emissions were very irregular, with rapid and extreme fluctuations. The pilot plant was operated at an empty bed residence time (EBRT) ranging from 10 to 40 sec, and good removal efficiencies of VOCs were usually obtained. When a buffering activated carbon prefil…
Computational fluid dynamics and its application to transport processes
2007
Fluid transport behaviour is of great importance within the chemical process industry and in biotechnology. The complexity of this behaviour, reflected in the nature of the fundamental partial differential equations which describe it analytically, means that it has to be treated by numerical methods. In this paper the basic equations are given, and the approaches necessary to treat laminar and turbulent flows are carefully explained. As digital computers have increased in size, so has the comprehensiveness of the problems which can be treated, and the development of typical computer programs is described. Problems of accuracy and experimental validation are also surveyed, and it is shown th…
Thermo-mechanical post-buckling analysis of variable angle tow composite plate assemblies
2017
peer-reviewed The increasing use of composite materials for lightweight structural applications and the extended tailoring capabilities offered by variable stiffness laminates requires rapid and robust analysis tools that adequately describe the mechanical behaviour of such structures. In this work, a Rayleigh–Ritz solution for generally restrained multilayered stiffened variable angle tow plates in the post-buckling regime is presented. The plate model is based on first-order shear deformation theory and accounts for geometrical nonlinearity through von Kármán’s assumptions. General symmetric and unsymmetric stacking sequences are considered and Legendre orthogonal polynomials are employed…