CFD Challenge: Experimental Benchmarking Data for the Pressure Drop Across a Cerebral Aneurysm Model

2012 ◽  
Author(s):  
Paul Fahy ◽  
Michael Walsh ◽  
Francis Loth ◽  
Florentina Ene ◽  
Patrick Delassus ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Abdominal Aorta ◽  
Experimental Testing ◽  
Research Centre ◽  
Flow Conditions ◽  
The West ◽  
Type Flow ◽  
Institute Of Technology ◽  
Physiological Type ◽  
Aneurysm Model

Since 2006, the GMedTech biomedical research centre in the Galway Mayo Institute of Technology (GMIT) in the west of Ireland has developed capabilities for generating physiological type flow conditions through realistic vascular models based on medical images. The GMedTech centre has designed and developed a number of fully controlled and instrumented synchronised experimental test systems for testing in the abdominal aorta, coronary, venous and intracranial vessels with and without associated disease types. The experimental testing was performed by PhD candidate Paul Fahy and his supervisors Dr. Liam Morris and Dr. Patrick Delassus.

The Stability of Flow Through Porous Screens

1960 ◽  
Vol 64 (594) ◽  
pp. 359-362 ◽  
Author(s):  
P. G. Morgan
Keyword(s):  
Pressure Drop ◽  
Sufficient Information ◽  
Flow Conditions ◽  
Flow Through ◽  
The Stability

In many cases of the flow through porous screens, one may consider it to be made up of a number of jets passing through the openings of the screen. These jets are separated by a series of wakes behind the solid parts of the screen. The majority of investigations on the flow through such screens have been concerned with the measurement of pressure drop and its variation with different flow conditions; it has been assumed that the pressure is discontinuous at the screen itself and that the pressure drop coefficient Δp/½ρυ2 provides sufficient information, where Δp is the pressure drop across the screen, ρ the density of the fluid, and υ the velocity of approach to the screen.

A Study on Flow Boiling in Microchannel With Piranha Pin Fin

2015 ◽  
Author(s):  
X. Yu ◽  
C. Woodcock ◽  
Y. Wang ◽  
J. Plawsky ◽  
Y. Peles
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Transfer Performance ◽  
Flow Boiling ◽  
Transfer Performance ◽  
Flow Conditions ◽  
Pin Fin ◽  
Flow And Heat Transfer

In this paper we reported an advanced structure, the Piranha Pin Fin (PPF), for microchannel flow boiling. Fluid flow and heat transfer performance were evaluated in detail with HFE7000 as working fluid. Surface temperature, pressure drop, heat transfer coefficient and critical heat flux (CHF) were experimentally obtained and discussed. Furthermore, microchannels with different PPF geometrical configurations were investigated. At the same time, tests for different flow conditions were conducted and analyzed. It turned out that microchannel with PPF can realize high-heat flux dissipation with reasonable pressure drop. Both flow conditions and PPF configuration played important roles for both fluid flow and heat transfer performance. This study provided useful reference for further PPF design in microchannel for flow boiling.

High Speed Flow through Perforated Plates

1960 ◽  
Vol 64 (590) ◽  
pp. 103-105
Author(s):  
P. G. Morgan
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Perforated Plate ◽  
Wire Mesh ◽  
Flow Conditions ◽  
High Speed Flow ◽  
Perforated Plates ◽  
Speed Flow ◽  
Flow Through ◽  
Points Of View

The flow through porous screens has been widely studied from both the theoretical and experimental points of view. The most widely used types of screen are the wire mesh and the perforated plate, and the majority of the literature has been concerned with the former. Several attempts have been made to correlate the parameters governing the flow through such screens, i.e. the pressure drop, the flow conditions and the geometry of the mesh.

Overview on Fusion Nuclear Technology Experimental Testing

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Slavomir Entler ◽  
Jan Kysela
Keyword(s):  
Eutectic Alloy ◽  
Nuclear Reactor ◽  
Experimental Testing ◽  
High Heat ◽  
Neutron Field ◽  
Research Centre ◽  
Nuclear Technology ◽  
High Heat Flux ◽  
Research Activities ◽  
Experimental Facilities

Research Centre Rez in the Czech Republic has carried out a number of research and development activities on the nuclear technology of the fusion reactor International Thermonuclear Experimental Reactor (ITER). These contributions have led to the development of numerous experimental facilities. The initial experimental research related to ITER was focused on the technology of the LiPb eutectic alloy, and a production unit and technological channel were constructed. At a later time, material tests were performed in the neutron field of the LVR-15 research nuclear reactor. Interactions of EUROFER 97 and the LiPb eutectic alloy were examined in in-pile and out-pile tests, and the technology of the LiPb was developed. First wall mock-ups were in-pile and out-pile tested under high heat flux (HHF) cycle loads. At present, a full-size mock-up of the ITER Test Blanket System (TBS) and an HHF testing complex are constructed. This paper provides an overview of the research activities and experimental facilities.

High Speed Flow Through Wire Gauzes

1959 ◽  
Vol 63 (584) ◽  
pp. 474-475 ◽  
Author(s):  
P. G. Morgan
Keyword(s):  
Pressure Drop ◽  
Pressure Loss ◽  
High Speed ◽  
Static Pressure ◽  
Flow Conditions ◽  
High Speed Flow ◽  
Speed Flow ◽  
Wire Gauze ◽  
Flow Through

The Flow of Fluids through screens has been widely studied with particular importance being attached to the measurement of the pressure drop caused by a screen and its relation to the screen geometry and the flow conditions. The majority of the investigations have been carried out on wire gauze screens mounted in ducts with air passing through them, the static pressure being measured on either side of the gauze. Attempts have been made by Weighardt Annand and Grootenhuisto correlate the gauze geometry with the pressure drop and to enable the pressure loss over a given screen and with given flow conditions to be predicted.

Alveolar pressure-airflow characteristics in humans breathing air, He-O2, and SF6-O2

1981 ◽  
Vol 51 (4) ◽  
pp. 1033-1037 ◽  
Author(s):  
A. S. Slutsky ◽  
J. M. Drazen ◽  
C. F. O'Cain ◽  
R. H. Ingram
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Coefficient Of Friction ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Sectional Area ◽  
Alveolar Pressure ◽  
Flow Conditions ◽  
Cross Sectional ◽  
The Coefficient Of Friction

In a system of rigid tubes under steady flow conditions, the coefficient of friction [CF = 2 delta P/(rho V2/A2)] (where delta P is pressure drop, rho is density, V is flow, and A is cross-sectional area) should be a unique function of Reynolds' number (Re). Recently it has been shown that at any given Re, the value of CF using transpulmonary pressure (PL) was lower when breathing He-O2 compared with air (Lisboa et al., J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 48: 878–885, 1980). One explanation for this discontinuity is that PL includes the pressure drop due to tissue viscance, which is independent of V, and thus would lead to an overestimate of CF on air compared with He-O2 at any Re. We tested this hypothesis by measuring V related to alveolar pressure, rather than PL, in normal subjects breathing air, He-O2, and SF6-O2. In each subject, for a given Re, CF was greatest breathing SF6-O2 and lowest breathing He-O2, similar to results using PL. Thus tissue viscance is not the sole cause of the discontinuous plot of CF vs. Re, and this phenomenon must be due to other factors, such as changing geometry or nonsteady behavior.

Internal flow analysis of a porous burner via CFD

2019 ◽  
Vol 29 (8) ◽  
pp. 2666-2683 ◽  
Author(s):  
Ali H. Abdulkarim ◽  
Ali Ates ◽  
Kemal Altinisik ◽  
Eyüb Canli
Keyword(s):  
Pressure Drop ◽  
Static Pressure ◽  
Porous Metal ◽  
Cfd Analysis ◽  
Flow Conditions ◽  
Content Type ◽  
Flow Mixing ◽  
Porous Burner ◽  
Flow Domain ◽  
Burner Design

Purpose This study aims to introduce a metal porous burner design. Literature is surveyed in a comprehensive manner to relate the current design with ongoing research. A demonstrative computational fluid dynamics (CFD) analysis is presented with projected flow conditions by means of a common commercial CFD code and turbulence model to show the flow-related features of the proposed burner. The porous metal burner has a novel design, and it is not commercially available. Design/methodology/approach Based on the field experience about porous burners, a metal, cylindrical, two-staged, homogenous porous burner was designed. Literature was surveyed to lay out research aspects for the porous burners and porous media. Three dimensional solid computer model of the burner was created. The flow domain was extracted from the solid model to use in CFD analysis. A commercial computational fluid dynamics code was utilized to analyze the flow domain. Projected flow conditions for the burner were applied to the CFD code. Results were evaluated in terms of homogenous flow distribution at the outer surface and flow mixing. Quantitative results are gathered and are presented in the present report by means of contour maps. Findings There aren’t any flow sourced anomalies in the flow domain which would cause an inefficient combustion for the application. An accumulation of gas is evident around the top flange of the burner leading to higher static pressure. Generally, very low pressure drop throughout the proposed burner geometry is found which is regarded as an advantage for burners. About 0.63 Pa static pressure increase is realized on the flange surface due to the accumulation of the gas. The passage between inner and outer volumes has a high impact on the total pressure and leads to about 0.5 Pa pressure drop. About 0.03 J/kg turbulent kinetic energy can be viewed as the highest amount. Together with the increase in total enthalpy, total amount of energy drawn from the flow is 0.05 J/kg. More than half of it spent through turbulence and remaining is dissipated as heat. Outflow from burner surface can be regarded homogenous though the top part has slightly higher outflow. This can be changed by gradually increasing pore sizes toward inlet direction. Research limitations/implications Combustion via a porous medium is a complex phenomenon since it involves multiple phases, combustion chemistry, complex pore geometries and fast transient responses. Therefore, experimentation is used mostly. To do a precise computational analysis, strong computational power, parallelizing, elaborate solid modeling, very fine meshes and small time steps and multiple models are required. Practical implications Findings in the present work imply that a homogenous gas outflow can be attained through the burner surfaces while very small pressure drop occurs leading to less pumping power requirement which is regarded as an advantage. Flow mixing is realizable since turbulent kinetic energy is distinguished at the interface surface between inner and outer volumes. The porous metal matrix burner offers fluid mixing and therefore better combustion efficiency. The proposed dimensions are found appropriate for real-world application. Originality/value Conducted analysis is for a novel burner design. There are opportunities both for scientific and commercial fields.

scholarly journals Surge Limit Prediction for Automotive Air-Charged Systems

2019 ◽  
Vol 4 (4) ◽  
pp. 34
Author(s):  
Johannes Bühler ◽  
Sebastian Leichtfuß ◽  
Heinz-Peter Schiffer ◽  
Thomas Lischer ◽  
Simon Raabe
Keyword(s):  
Development Process ◽  
Experimental Testing ◽  
Piping System ◽  
Economic Perspective ◽  
Flow Conditions ◽  
Strong Variation ◽  
Piston Engine ◽  
Hot Gas ◽  
Compressor Surge ◽  
Compressor Aerodynamics

Compressor surge has been investigated and predicted since the early days of turbomachinery research. Experimental testing of turbomachinery applications is still needed to determine whether stable compressor operation is possible in the expected application regime. Measuring compressor maps and operating ranges on hot gas test stands is common. The test benches are designed and optimized to ensure ideal inflow and outflow conditions as well as low measurement uncertainty. Compressor maps are used to match turbocharger and application. However, a shift in surge limit, caused by the piping system or application, can only be adequately addressed with full engine tests. Ideal measurements use the corresponding piston engine in the charged-air system. This can only take place in the development process, when surge detection is unfavorable from an economic perspective. The surge model for turbochargers presented here is an extension of the Greitzer’s surge model, which considers the effect of inlet throttling. Application components, such as air filters, pipe elbows and flow straighteners, reduce pressure in front of the compressor and flow conditions might differ from those in laboratory testing. Experimental results gathered from the hot gas test stand at TU Darmstadt indicate strong variation in surge limit, influenced by inlet throttling. An extension to the surge model is developed to explain the observed phenomena. The model was validated using extensive experimental variations and matches the experienced surge limit shift. Additional measurements with a piston engine downstream of the turbocharger demonstrated the validity of the surge model. The results also show that surge is a system-dependent phenomenon, influenced by compressor aerodynamics and boundary conditions.

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