Modeling of Dissolved Gas Effect on Liquid Transients

2005 ◽  
Vol 73 (1) ◽  
pp. 112-119
Author(s):  
Mohand Kessal ◽  
Rachid Bennacer
Keyword(s):  
Liquid Mixture ◽  
Ideal Gas ◽  
Dissolved Gas ◽  
Mixture Flow ◽  
Ideal Gas Law ◽  
Elastic Pipeline ◽  
Suitable Treatment ◽  
Gas Cavity ◽  
Space Expansion ◽  
Gas Effect

Transient cavitation of a homogeneous gas-liquid mixture flow is modeled for an elastic pipeline by using the classical conservation equations of each phase, which are, later on, written in dimensionless form. The later is resolved by a second order finite difference scheme for which a flux corrective transport algorithm is added as an additional step, in order to accomplish a suitable treatment of the shock problem. The flow gives rise to a localized vapor+gas cavity for which time and space expansion is calculated from the corresponding compatibility relation, continuity equation and ideal gas law. Also, effect of the degassing phenomenon, on this cavity and on the dynamic parameters, is reproduced from a macroscopic bubble growth model. Obtained results are discussed and compared with ones given by experimental data.

Making sense of sensemaking: using the sensemaking epistemic game to investigate student discourse during a collaborative gas law activity

2021 ◽  
Author(s):  
Kevin H. Hunter ◽  
Jon-Marc G. Rodriguez ◽  
Nicole M. Becker
Keyword(s):  
Problem Solving ◽  
Conceptual Understanding ◽  
Ideal Gas ◽  
Interactive Simulation ◽  
Structural Components ◽  
Student Discourse ◽  
Coding Scheme ◽  
Making Sense ◽  
Ideal Gas Law ◽  
The Ideal

Beyond students’ ability to manipulate variables and solve problems, chemistry instructors are also interested in students developing a deeper conceptual understanding of chemistry, that is, engaging in the process of sensemaking. The concept of sensemaking transcends problem-solving and focuses on students recognizing a gap in knowledge and working to construct an explanation that resolves this gap, leading them to “make sense” of a concept. Here, we focus on adapting and applying sensemaking as a framework to analyze three groups of students working through a collaborative gas law activity. The activity was designed around the learning cycle to aid students in constructing the ideal gas law using an interactive simulation. For this analysis, we characterized student discourse using the structural components of the sensemaking epistemic game using a deductive coding scheme. Next, we further analyzed students’ epistemic form by assessing features of the activity and student discourse related to sensemaking: whether the question was framed in a real-world context, the extent of student engagement in robust explanation building, and analysis of written scientific explanations. Our work provides further insight regarding the application and use of the sensemaking framework for analyzing students’ problem solving by providing a framework for inferring the depth with which students engage in the process of sensemaking.

scholarly journals Induction of Changes in Internal Gas Pressure of Bulky Plant Organs by Temperature Gradients

1990 ◽  
Vol 115 (2) ◽  
pp. 308-312 ◽  
Author(s):  
Kenneth A. Corey ◽  
Zhi-Yi Tan
Keyword(s):  
Bath Temperature ◽  
Ideal Gas ◽  
Gas Pressure ◽  
Temperature Gradients ◽  
Maximum Pressure ◽  
Plant Organs ◽  
Ideal Gas Law ◽  
Increasing Temperature ◽  
Pressure Changes

Water manometers were connected to fruits of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and then fruits were submerged in water baths providing initial temperature gradients between fruit and water of 0 to 19C. Apple (Malus domestics Borkh.) fruits, carrot (Daucus carota L.) roots, witloof chicory (Cichorium intybus L.) roots, rhubarb Rheum rhabarbarum L.) petioles, and pokeweed (Phytolacca americana L.) stems were subjected to water bath temperature gradients of 5C. Internal partial vacuums developed in all organs within minutes of imposing the gradients. The maximum partial vacuums in tomato and pepper fruits increased with increasing temperature gradients. Uptake of water accompanied changes in internal pressure reaching maxima of 17% (w/w) and 2% (w/w) of pepper and tomato fruits, respectively, after 22 hours. Maximum pressure changes achieved in bulky organs deviated from those predicted by the ideal gas law, possibly due to concomitant changes in gas pressure upon replacement of intercellular spaces with water and dissolution of CO2. Partial vacuums also developed in pepper fruits, rhubarb petioles, and pokeweed stems following exposure to air 15C cooler than initial organ temperatures. Results point to the role of temperature gradients in the transport of liquids and gases in plant organs.

What Happens When We have Winter Heating of Our Rooms?

2020 ◽  
Vol 02 (01) ◽  
pp. 2020001
Author(s):  
Dulli C. Agrawal
Keyword(s):  
Internal Energy ◽  
Old Age ◽  
Ideal Gas ◽  
Van Der Waals Gas ◽  
Constant Weight ◽  
Gas Laws ◽  
Ideal Gas Law ◽  
Marginal Change ◽  
Three Stages ◽  
The Ideal

The illustrious question by German Astrophysicist R. Emden, “Why do we have winter heating?” has been re-examined for air following both the ideal and imperfect gas laws; the internal energy of the air in the room remains unaffected in the former case whereas it increases marginally for the latter one. The findings corresponding to ideal gas law were correlated by Emden with the mass of a person which does not change even though food is constantly consumed. This example corresponds to adulthood when the mass of a person remains more or less constant. But the marginal change of internal energy in the case of van der Waals gas is consistent with three stages of a person — initially a person grows during childhood followed by adulthood when he has more or less constant weight and finally in old age, it deteriorates.

The performance of spiral groove dry gas seal under choked flow condition considering the real gas effect

2019 ◽  
Vol 234 (4) ◽  
pp. 554-566
Author(s):  
Hengjie Xu ◽  
Pengyun Song ◽  
Wenyuan Mao ◽  
Qiangguo Deng
Keyword(s):  
Carbon Dioxide ◽  
Flow Condition ◽  
Ideal Gas ◽  
Leakage Rate ◽  
Spiral Groove ◽  
Real Gas ◽  
Dry Gas Seal ◽  
Choked Flow ◽  
Real Gas Effect ◽  
Gas Effect

By taking carbon dioxide and hydrogen as lubricating gas, respectively, this paper presents an analysis on the pressure characteristics and temperature distribution of spiral groove dry gas seal which influenced by real gas effect under choked flow condition. Numerical results show that the deviation between real gas and ideal gas, which expressed by the deviation degree between compressibility factor Z and 1, is the main reason for real gas effect affecting sealing performance. Compared with ideal gas model, real gas effect raises exit pressure, opening force, leakage rate, Mach number in dam region, and temperature for carbon dioxide ( Z < 1), while it decreases those characteristics for hydrogen ( Z > 1) under the same operating conditions. In addition, choked flow effect increases opening force and reduces leakage rate and temperature-drop between entrance and exit of sealing clearance. Meanwhile, it may cause an unstable behavior for the seal.

Bending Behavior of Plain-Woven Fabric Air Beams: Fluid-Structure Interaction Approach

2006 ◽  
Author(s):  
Paul V. Cavallaro ◽  
Ali M. Sadegh ◽  
Claudia J. Quigley
Keyword(s):  
Finite Element ◽  
Ideal Gas ◽  
Woven Fabric ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Ideal Gas Law ◽  
Biaxial Tests ◽  
Structural Responses ◽  
Bending Behavior ◽  
Interaction Approach

A swatch of plain-woven fabric was subjected to biaxial tests and its material characterization was performed. The stress-strain relations of the fabric were determined and directly used in finite element models of an air beam, assumed constructed with the same fabric, subjected to inflation and bending events. The structural responses to these events were obtained using the ABAQUS-Explicit[1] finite element solver for a range of pressures including those considered typical in safe operations of air inflated structures. The models accounted for the fluid-structure interactions between the air and the fabric. The air was treated as a compressible fluid in accordance with the Ideal Gas Law and was subjected to adiabatic constraints during bending. The fabric was represented with membrane elements and several constitutive cases including linear elasticity and hyperelasticity were studied. The bending behavior for each constitutive case is presented and discussions for their use and limitations follow.

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