Calculations of Real-Gas Effects in Flow Through Critical-Flow Nozzles

1964 ◽  
Vol 86 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Robert C. Johnson
Keyword(s):  
Mass Flow ◽  
Room Temperature ◽  
The Other ◽  
Critical Flow ◽  
Real Gas ◽  
One Dimensional ◽  
Real Gas Effects ◽  
Computer Calculations ◽  
Flow Through

Computer calculations have been made of how real-gas effects modify the conventional one-dimensional equations for mass flow of air, nitrogen, oxygen, hydrogen, argon, helium, and steam through a nozzle. The results indicate that for critical flow of air, at room temperature and 100 atmospheres pressure, real-gas effects of 3 1/2 percent exist. Similar magnitudes are found for the other gases.

Crystal Distortions Associated with Magnetic Ordering in the Antiferromagnetic Compound VF2

1970 ◽  
Vol 14 ◽  
pp. 433-440
Author(s):  
W. S. McCain ◽  
D. L. Albright ◽  
W. O. J. Boo
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Magnetic Ordering ◽  
The Body ◽  
The Other ◽  
Magnetic Interactions ◽  
One Dimensional ◽  
Lattice Constants ◽  
Vanadium Ions

AbstractLattice constants were measured as a function of temperature by single crystal diffracrometry in the temperature range which includes the Néel temperature of VF2(TN= 7°K). The lattice constants of VF2(D4h14=P42m n m) were measured from room temperature down to 4.2°K. In this range rhe tetragonal c-axis contracts 0.58% from 3.2359 Å (RT) to 3.2170 Å (4.2°K). On the other hand, the a-axes show a net expansion of 0.18% from 4.8023 Å (RT) to 4.8110 Å at 4.2°K. The temperature dependence of the lattice constants can be correlated with anisotropy of exchange forces. Vanadium Ions occupy the center and corner positions of the unit cell. Strong magnetic interactions are directed parallel to the c-axis >001< with considerably weaker interactions parallel to the body diagonals >111< The relative strengths of the two exchange integrals are J >001< = 50 J >111<. As a consequence the magnetic ordering is one-dîmensional along the c-axis and the associated distortions arise from the strong magnetic interactions along this axis.

Langmuir-Blodgett films of One-dimensional Nanowires composed of Amphiphilic Tetrathiafulvalenes and Electron Acceptor

2008 ◽  
Vol 1144 ◽  
Author(s):  
Yoko Tatewaki ◽  
Junko Takizawa ◽  
Tatsuya Hatanaka ◽  
Mutsumi Kimura ◽  
Hirofusa Shirai
Keyword(s):  
Electron Acceptor ◽  
Room Temperature ◽  
The Other ◽  
Water Interface ◽  
One Dimensional ◽  
Langmuir Blodgett ◽  
Electrical Conductivities ◽  
Air Water Interface ◽  
Langmuir Blodgett Films ◽  
Mixed Layers

ABSTRACTWe found that novel amphiphilic tetrathiafulvalene (TTF; 1) organized into supramolecular assemblies by the addition of electron acceptor 2,3,5,6-tetrafluoro-7,7'f,8,8'f-tetracyano-p-quinodimethane (F4TCNQ) at the air-water interface. The assemblies on the air-water interface can be transferred onto the surface of mica and the morphologies of transferred films were investigated by AFM. The morphology of Langmuir-Blodgett films strongly depended on the ratio between 1 and F4TCNQ. Film of 1:1 mixture of 1 and F4TCNQ formed nanoscopic wires having an average dimension of 5.0 (height) × 70 (width) × 3000 (length) nm. On the other hand, the film of 2:1 mixture of 1 and F4TCNQ showed the mixed domains of wires and flat monolayers. Thus, the completely charge-transferred complex (1+)(F4TCNQ-) formed one-dimensional nanowires having a micrometer length. Room temperature electrical conductivities of cast film for 1:1 and 2:1 mixed layers of 1 and F4TCNQ were 2.4 × 10−4 and 8.0 × 10−5 S cm−1, respectively.

Mathematical aspects of the theory of inviscid hypersonic flow

1991 ◽  
Vol 335 (1637) ◽  
pp. 121-138 ◽  
Keyword(s):  
Chemical Reactions ◽  
Mathematical Analysis ◽  
Solution Structure ◽  
Well Posedness ◽  
Two Dimensional ◽  
Open Problems ◽  
Real Gas ◽  
One Dimensional ◽  
Two Dimensional Flow ◽  
Real Gas Effects

This paper reviews some differential equations arising in the theory of inviscid hypersonic gasdynamics. The only real-gas effects that we have incorporated are simple models for chemical reactions. After describing what is known about the solution structure of these equations in unsteady one-dimensional and steady two- dimensional flow, we make some conjectures about the well-posedness and regularization of certain specific open problems which have not yet been susceptible to mathematical analysis.

scholarly journals Calculations of the Flow of Natural Gas Through Critical Flow Nozzles

1970 ◽  
Vol 92 (3) ◽  
pp. 580-586 ◽  
Author(s):  
R. C. Johnson
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Range ◽  
Gas Mixtures ◽  
Empirical Method ◽  
Critical Flow ◽  
One Dimensional ◽  
Rate Calculation

The mass flow rate of methane and 19 natural gas mixtures through critical flow nozzles has been calculated. The calculation assumes the flow to be one-dimensional and isentropic. The pressure range is 0 to 1000 psi and the temperature range is from 450 to 700 deg Rankine. From a study of the results, a simple empirical method for making this mass flow rate calculation is proposed. This method would apply to natural gas mixtures whose composition is known and whose components have no more than four carbon atoms.

Performance of a Small-Sized, Critical Flowmeter Assembly

1965 ◽  
Vol 87 (4) ◽  
pp. 1025-1027
Author(s):  
D. E. Dye
Keyword(s):  
Mass Flow ◽  
Discharge Coefficient ◽  
Flow Equation ◽  
Average Error ◽  
Critical Flow ◽  
Flow Rates ◽  
One Dimensional ◽  
Upstream Pressure ◽  
Mass Flow Rates ◽  
Low Mass

Measurement of low mass-flow rates was readily accomplished by development of two similar flowmetering assemblies. Each assembly consisted of five 0.016 to 0.070-in. diameter critical-flow nozzles and individual control valves connected between common inlet and exit manifolds. Mass-flow rates through each nozzle were determined over a range of upstream pressure and temperature. The probable deviations in the measured data are approximately ≠0.83 percent. Discharge coefficients were calculated from the calibration results using the well-known one-dimensional critical-flow equation. An average error of ≠2.5 percent in the discharge coefficient is possible because of the difficulty in determining true throat areas of these small-sized nozzles.

An Assessment of Shock-Disturbances Interaction Considering Real Gas Effects

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
K. Hejranfar ◽  
S. Rahmani
Keyword(s):  
Theoretical Analysis ◽  
The Body ◽  
Mathematical Function ◽  
Perfect Gas ◽  
Real Gas ◽  
One Dimensional ◽  
Wide Range ◽  
Different Types ◽  
Real Gas Effects ◽  
Analytical Relations

In this study, a theoretical analysis is performed to assess the interaction of freestream disturbances with a plane normal shock considering real gas effects. Such effects are important in a field with high velocities and high temperatures. To perform the theoretical analysis, the downstream disturbances field is expressed as a mathematical function of the upstream one by incorporating real gas effects in the formulation. Here, the linearized one-dimensional perturbed unsteady Euler equations are used for the classification of the downstream/upstream disturbances field and the linearized one-dimensional perturbed Rankine–Hugoniot equations are applied to provide a relationship between the disturbances field of two sides of the shock. To incorporate real gas effects in the formulation, real gas relations and equilibrium air curve-fits are used in the resulting system of equations. The general formulation presented here may be simplified to derive Morkovin's formulation by the perfect gas assumption. The magnitudes of downstream disturbances field resulting from different types of upstream disturbances field (entropy wave and fast/slow acoustic waves) with the shock are expressed by appropriate analytical relations. Results for different disturbance variables are presented for a wide range of upstream Mach number considering real gas effects and compared with those of the perfect gas and some conclusions are made. The effects of the presence of body are also studied theoretically and the analytical relations for the magnitude of the pressure disturbance at the body for different types of upstream disturbances field considering real gas effects are provided and their results are presented and discussed.

Effect of high beta values on mass flow through critical flow nozzles

2000 ◽  
Vol 11 (4) ◽  
pp. 351-356
Author(s):  
D.G Stewart ◽  
J.T.R Watson ◽  
A.M Vaidya
Keyword(s):  
Mass Flow ◽  
Critical Flow ◽  
Flow Through ◽  
High Beta
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