scholarly journals High Pressure Falling Sinker Liquid Viscosity Determination without Supplementary Density Data: A New Approach

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Minyu Zeng ◽  
Carl Schaschke
Keyword(s):  
High Pressure ◽  
Published Data ◽  
Viscosity Data ◽  
Liquid Density ◽  
Liquid Viscosity ◽  
New Approach ◽  
Density Data ◽  
Elevated Pressures ◽  
Viscosity Determination

Accurate measurement and determination of liquid viscosity data under high pressure conditions requires knowledge of liquid density data. In this study, a high pressure falling sinker-type viscometer was used to determine the viscosity of n-dodecane at elevated pressures up to 132 MPa without supplementary knowledge of liquid density. The viscometer, which involves the downward movement of a cylindrical sinker under the influence of gravity through the liquid contained within a closed tube, avoided the need for density data by repeating the sinker-timing experiments with two geometrically similar but different-sized sinkers thereby allowing the liquid density in the associated formulae to be eliminated. Furthermore, it was possible to subsequently derive liquid density. Both viscosity and density data were compared to published data for which good correlation was found for viscosity. To minimize errors, it is suggested that the two sinkers for such an approach should be of sufficiently differing densities.

scholarly journals Determination of liquid viscosity at high pressure by DLS

2010 ◽  
Vol 215 ◽  
pp. 012073 ◽  
Author(s):  
K Fukui ◽  
Y Asakuma ◽  
K Maeda
Keyword(s):  
High Pressure ◽  
Liquid Viscosity

Laminar Flame Speed Measurements and Modeling of Pure Alkanes and Alkane Blends at Elevated Pressures

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
William Lowry ◽  
Jaap de Vries ◽  
Michael Krejci ◽  
Eric Petersen ◽  
Zeynep Serinyel ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Turbines ◽  
Laminar Flame ◽  
Flame Speed ◽  
Published Data ◽  
Laminar Flame Speed ◽  
Binary Blends ◽  
Elevated Pressures ◽  
True Value

Alkanes such as methane, ethane, and propane make up a large portion of most natural gas fuels. Natural gas is the primary fuel used in industrial gas turbines for power generation. Because of this, a fundamental understanding of the physical characteristics such as the laminar flame speed is necessary. Most importantly, this information is needed at elevated pressures to have the most relevance to the gas turbine industry for engine design. This study includes experiments performed at elevated pressures, up to 10 atm initial pressure, and investigates the fuels in a pure form as well as in binary blends. Flame speed modeling was done using an improved version of the kinetics model that the authors have been developing over the past few years. Modeling was performed for a wide range of conditions, including elevated pressures. Experimental conditions include pure methane, pure ethane, 80/20 mixtures of methane/ethane, and 60/40 mixtures of methane/ethane at initial pressures of 1 atm, 5 atm, and 10 atm. Also included in this study are pure propane and 80/20 methane/propane mixtures at 1 atm and 5 atm. The laminar flame speed and Markstein length measurements were obtained from a high-pressure flame speed facility using a constant-volume vessel. The facility includes optical access, a high-speed camera, a schlieren optical setup, a mixing manifold, and an isolated control room. The experiments were performed at room temperature, and the resulting images were analyzed using linear regression. The experimental and modeling results are presented and compared with previously published data. The data herein agree well with the published data. In addition, a hybrid correlation was created to perform a rigorous uncertainty analysis. This correlation gives the total uncertainty of the experiment with respect to the true value rather than reporting the standard deviation of a repeated experiment. Included in the data set are high-pressure results at conditions where in many cases for the single-component fuels few data existed and for the binary blends no data existed prior to this study. Overall, the agreement between the model and data is excellent.

scholarly journals Development of Characterization Techniques of Thermodynamic and Physical Properties Applied to the CO2-DMSO Mixture

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Brice Calvignac ◽  
Elisabeth Rodier ◽  
Jean-Jacques Letourneau ◽  
Jacques Fages
Keyword(s):  
Process Design ◽  
Published Data ◽  
Viscosity Data ◽  
Pressure Measurements ◽  
Co2 Solubility ◽  
Volumetric Expansion ◽  
Characterization Techniques ◽  
Dmso System ◽  
Good Agreement

This work is focused on the development of new characterization techniques of physical and thermodynamic properties. These techniques have been validated using the binary system DMSO-CO2 for which several studies of characterization have been well documented. We focused on the DMSO-rich phase and we carried out measurements of volumetric expansion, density, viscosity and CO2 solubility at 298.15, 308.15 and 313.15 K and pressures up to 9 MPa. The experimental procedures were compared and validated with the available literature data on SC-CO2-DMSO system. We made density and CO2 solubility measurements, using respectively the vibrating tube technology and two static analytical methods. Lastly, we developed an innovative falling body viscosimeter for high pressure measurements. All the measurements made are in good agreement with the already published data in spite of very different experimental techniques. This work is a contribution to the understanding of the DMSO-CO2 binary as it implements new viscosity data. Moreover, it opens new perspectives about the determination of the properties of other systems such as polymers-CO2 and fats-CO2, which are essential for supercritical process design such as extraction, crystallization, chromatography and synthesis reaction.

scholarly journals A MultiScale Gibbs-Helmholtz Constrained Cubic Equation of State

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Angelo Lucia
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Internal Energy ◽  
Equations Of State ◽  
Energy Parameter ◽  
New Approach ◽  
Cubic Equation Of State ◽  
Cubic Equation ◽  
Dynamics Simulations

This paper presents a radically new approach to cubic equations of state (EOS) in which the Gibbs-Helmholtz equation is used to constrain the attraction or energy parameter, a. The resulting expressions for for pure components and for mixtures contain internal energy departure functions and completely avoid the need to use empirical expressions like the Soave alpha function. Our approach also provides a novel and thermodynamically rigorous mixing rule for . When the internal energy departure function is computed using Monte Carlo or molecular dynamics simulations as a function of current bulk phase conditions, the resulting EOS is a multiscale equation of state. The proposed new Gibbs-Helmholtz constrained (GHC) cubic equation of state is used to predict liquid densities at high pressure and validated using experimental data from literature. Numerical results clearly show that the GHC EOS provides fast and accurate computation of liquid densities at high pressure, which are needed in the determination of gas hydrate equilibria.

Determination of high-pressure liquid density for n-perfluorohexane and n-perfluorononane

2004 ◽  
Vol 220 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Manuel M Piñeiro ◽  
David Bessières ◽  
Jorge M Gacio ◽  
Henri Saint-Guirons ◽  
José Luis Legido
Keyword(s):  
High Pressure ◽  
Liquid Density

Laminar Flame Speed Measurements and Modeling of Pure Alkanes and Alkane Blends at Elevated Pressures

2010 ◽  
Author(s):  
William Lowry ◽  
Jaap de Vries ◽  
Michael Krejci ◽  
Eric Petersen ◽  
Zeynep Serinyel ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Turbines ◽  
Laminar Flame ◽  
Flame Speed ◽  
Published Data ◽  
Laminar Flame Speed ◽  
Binary Blends ◽  
Elevated Pressures ◽  
True Value

Alkanes such as methane, ethane, and propane make up a large portion of most natural gas fuels. Natural gas is the primary fuel used in industrial gas turbines for power generation. Because of this, a fundamental understanding of the physical characteristics such as the laminar flame speed is necessary. Most importantly, this information is needed at elevated pressures to have the most relevance to the gas turbine industry for engine design. This study includes experiments performed at elevated pressures, up to 10-atm initial pressure, and investigates the fuels in a pure form as well as in binary blends. Flame speed modeling was done using an improved version of the kinetics model that the authors have been developing over the past few years. Modeling was performed for a wide range of conditions, including elevated pressures. Experimental conditions include pure methane, pure ethane, 80/20 mixtures of methane/ethane, and 60/40 mixtures of methane/ethane at initial pressures of 1, 5, and 10 atm. Also included in this study are pure propane and 80/20 methane/propane mixtures at 1 and 5 atm. The laminar flame speed and Markstein Length measurements were obtained from a high-pressure flame speed facility using a constant-volume vessel. The facility includes optical access, a high-speed camera, a schlieren optical setup, a mixing manifold, and an isolated control room. The experiments were performed at room temperature, and the resulting images were analyzed using linear regression. The experimental and modeling results are presented and compared to previously published data. The data herein agree well with the published data. In addition, a hybrid correlation was created to perform a rigorous uncertainty analysis. This correlation gives the total uncertainty of the experiment with respect to the true value rather than reporting the standard deviation of a repeated experiment. Included in the data set are high-pressure results at conditions where in many cases for the single-component fuels few data existed and for the binary blends no data existed prior to this study. Overall, the agreement between the model and data is excellent.

Social organization in the Orcadian Neolithic: identification of elite domestic structures and settlements through analysis of excavation data

2018 ◽  
Vol 40 (1) ◽  
pp. 25-53 ◽  
Author(s):  
David MacInnes
Keyword(s):  
Social Organization ◽  
Qualitative Data ◽  
Social Hierarchy ◽  
Published Data ◽  
Early Neolithic ◽  
Late Neolithic ◽  
New Approach ◽  
Qualitative Evidence ◽  
Methods Of Analysis ◽  
The Subject

The nature of social organization during the Orcadian Neolithic has been the subject of discussion for several decades with much of the debate focused on answering an insightful question posed by Colin Renfrew in 1979. He asked, how was society organised to construct the larger, innovative monuments of the Orcadian Late Neolithic that were centralised in the western Mainland? There are many possible answers to the question but little evidence pointing to a probable solution, so the discussion has continued for many years. This paper takes a new approach by asking a different question: what can be learned about Orcadian Neolithic social organization from the quantitative and qualitative evidence accumulating from excavated domestic structures and settlements?In an attempt to answer this question, quantitative and qualitative data about domestic structures and about settlements was collected from published reports on 15 Orcadian Neolithic excavated sites. The published data is less extensive than hoped but is sufficient to support a provisional answer: a social hierarchy probably did not develop in the Early Neolithic but almost certainly did in the Late Neolithic, for which the data is more comprehensive.While this is only one approach of several possible ways to consider the question, it is by exploring different methods of analysis and comparing them that an understanding of the Orcadian Neolithic can move forward.

The Dudley Lee Case: A new approach to factual causation and its implications for transformative jurisprudence

2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter
Keyword(s):  
Case Note ◽  
Constitutional Court ◽  
Recent Contribution ◽  
New Approach ◽  
State Accountability ◽  
The Law ◽  
Transformative Impact ◽  
Constitutional Jurisprudence ◽  
Law Of Delict

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.

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