**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**20

# Search results for: equation of state

##### 20 Three-Dimensional, Non-Linear Finite Element Analysis of Bullet Penetration through Thin AISI 4340 Steel Target Plate

**Authors:**
Abhishek Soni,
A. Kumaraswamy,
M. S. Mahesh

**Abstract:**

**Keywords:**
AISI 4340 steel,
ballistic impact simulation,
bullet
penetration,
non-linear FEM.

##### 19 Quantum Statistical Mechanical Formulations of Three-Body Problems via Non-Local Potentials

**Authors:**
A. Maghari,
V. H. Maleki

**Abstract:**

**Keywords:**
Statistical mechanics,
Nonlocal separable potential,
three-body interaction,
Faddeev equations.

##### 18 Conformal Invariance in F (R, T) Gravity

**Authors:**
Pyotr Tsyba,
Olga Razina,
Ertan Güdekli,
Ratbay Myrzakulov

**Abstract:**

In this paper we consider the equation of motion for the F (R, T) gravity on their property of conformal invariance. It is shown that in the general case, such a theory is not conformal invariant. Studied special cases for the functions v and u in which can appear properties of the theory. Also we consider cosmological aspects F (R, T) theory of gravity, having considered particular case F (R, T) = μR+νT^2. Showed that in this case there is a nonlinear dependence of the parameter equation of state from time to time, which affects its evolution.

**Keywords:**
Conformally invariance,
F (R,
T) gravity,
metric
FRW,
equation of motion,
dark energy.

##### 17 Correlation and Prediction of Biodiesel Density

**Authors:**
Nieves M. C. Talavera-Prieto,
Abel G. M. Ferreira,
António T. G. Portugal,
Rui J. Moreira,
Jaime B. Santos

**Abstract:**

The knowledge of biodiesel density over large ranges of temperature and pressure is important for predicting the behavior of fuel injection and combustion systems in diesel engines, and for the optimization of such systems. In this study, cottonseed oil was transesterified into biodiesel and its density was measured at temperatures between 288 K and 358 K and pressures between 0.1 MPa and 30 MPa, with expanded uncertainty estimated as ±1.6 kg⋅m- 3. Experimental pressure-volume-temperature (pVT) cottonseed data was used along with literature data relative to other 18 biodiesels, in order to build a database used to test the correlation of density with temperarure and pressure using the Goharshadi–Morsali–Abbaspour equation of state (GMA EoS). To our knowledge, this is the first that density measurements are presented for cottonseed biodiesel under such high pressures, and the GMA EoS used to model biodiesel density. The new tested EoS allowed correlations within 0.2 kg·m-3 corresponding to average relative deviations within 0.02%. The built database was used to develop and test a new full predictive model derived from the observed linear relation between density and degree of unsaturation (DU), which depended from biodiesel FAMEs profile. The average density deviation of this method was only about 3 kg.m-3 within the temperature and pressure limits of application. These results represent appreciable improvements in the context of density prediction at high pressure when compared with other equations of state.

**Keywords:**
Biodiesel,
Correlation,
Density,
Equation of state,
Prediction.

##### 16 Solubility of Water in CO2 Mixtures at Pipeline Operation Conditions

**Authors:**
Mohammad Ahmad,
Sander Gersen,
Erwin Wilbers

**Abstract:**

Carbon capture, transport and underground storage have become a major solution to reduce CO_{2} emissions from power plants and other large CO_{2} sources. A big part of this captured CO_{2} stream is transported at high pressure dense phase conditions and stored in offshore underground depleted oil and gas fields. CO_{2} is also transported in offshore pipelines to be used for enhanced oil and gas recovery. The captured CO_{2} stream with impurities may contain water that causes severe corrosion problems, flow assurance failure and might damage valves and instrumentations. Thus, free water formation should be strictly prevented. The purpose of this work is to study the solubility of water in pure CO_{2} and in CO_{2} mixtures under real pipeline pressure (90-150 bar) and temperature operation conditions (5-35°C). A set up was constructed to generate experimental data. The results show the solubility of water in CO_{2} mixtures increasing with the increase of the temperature or/and with the increase in pressure. A drop in water solubility in CO_{2} is observed in the presence of impurities. The data generated were then used to assess the capabilities of two mixture models: the GERG-2008 model and the EOS-CG model. By generating the solubility data, this study contributes to determine the maximum allowable water content in CO_{2 }pipelines.

**Keywords:**
Carbon capture and storage,
water solubility,
equation of states.

##### 15 Bubble Point Pressures of CO2+Ethyl Palmitate by a Cubic Equation of State and the Wong-Sandler Mixing Rule

**Authors:**
M. A. Sedghamiz,
S. Raeissi

**Abstract:**

This study presents three different approaches to estimate bubble point pressures for the binary system of CO2 and ethyl palmitate fatty acid ethyl ester. The first method involves the Peng-Robinson (PR) Equation of State (EoS) with the conventional mixing rule of Van der Waals. The second approach involves the PR EOS together with the Wong Sandler (WS) mixing rule, coupled with the UNIQUAC GE model. In order to model the bubble point pressures with this approach, the volume and area parameter for ethyl palmitate were estimated by the Hansen group contribution method. The last method involved the Peng-Robinson, combined with the Wong-Sandler method, but using NRTL as the GE model. Results using the Van der Waals mixing rule clearly indicated that this method has the largest errors among all three methods, with errors in the range of 3.96-6.22%. The PR-WS-UNIQUAC method exhibited small errors, with average absolute deviations between 0.95 to 1.97 percent. The PR-WS-NRTL method led to the least errors, where average absolute deviations ranged between 0.65-1.7%.

**Keywords:**
Bubble pressure,
Gibbs excess energy model,
mixing
rule,
CO2 solubility,
ethyl palmitate.

##### 14 Modification of Rk Equation of State for Liquid and Vapor of Ammonia by Genetic Algorithm

**Authors:**
S. Mousavian,
F. Mousavian,
V. Nikkhah Rashidabad

**Abstract:**

Cubic equations of state like Redlich–Kwong (RK) EOS have been proved to be very reliable tools in the prediction of phase behavior. Despite their good performance in compositional calculations, they usually suffer from weaknesses in the predictions of saturated liquid density. In this research, RK equation was modified. The result of this study show that modified equation has good agreement with experimental data.

**Keywords:**
Equation of state,
modification,
ammonia,
genetic algorithm.

##### 13 Tuning Cubic Equations of State for Supercritical Water Applications

**Authors:**
Shyh-Ming Chern

**Abstract:**

Cubic equations of state (EoS), popular due to their simple mathematical form, ease of use, semi-theoretical nature and reasonable accuracy, are normally fitted to vapor-liquid equilibrium *P*-*v*-*T* data. As a result, they often show poor accuracy in the region near and above the critical point. In this study, the performance of the renowned Peng-Robinson (PR) and Patel-Teja (PT) EoS’s around the critical area has been examined against the* P*-*v*-*T* data of water. Both of them display large deviations at critical point. For instance, PR-EoS exhibits discrepancies as high as 47% for the specific volume, 28% for the enthalpy departure and 43% for the entropy departure at critical point. It is shown that incorporating *P*-*v*-*T* data of the supercritical region into the retuning of a cubic EoS can improve its performance at and above the critical point dramatically. Adopting a retuned acentric factor of 0.5491 instead of its genuine value of 0.344 for water in PR-EoS and a new *F* of 0.8854 instead of its original value of 0.6898 for water in PT-EoS reduces the discrepancies to about one third or less.

**Keywords:**
Equation of state,
EoS,
supercritical water,
SCW.

##### 12 Mechanical Equation of State in an Al-Li Alloy

**Authors:**
Jung-Ho Moon,
Tae Kwon Ha

**Abstract:**

Existence of plastic equation of state has been investigated by performing a series of load relaxation tests at various temperatures using an Al-Li alloy. A plastic equation of state is first developed from a simple kinetics consideration for a mechanical activation process of a leading dislocation piled up against grain boundaries. A series of load relaxation test has been conducted at temperatures ranging from 200 to 530^{o}C to obtain the stress-strain rate curves. A plastic equation of state has been derived from a simple consideration of dislocation kinetics and confirmed by experimental results.

**Keywords:**
Plastic equation of state,
Dislocation kinetics,
Load relaxation test,
Al-Li alloy,
Microstructure.

##### 11 On the use of Ionic Liquids for CO2 Capturing

**Authors:**
Emad Ali,
Inas Alnashef,
Abdelhamid Ajbar,
Mohamed HadjKali,
Sarwono Mulyono

**Abstract:**

In this work, ionic liquids (ILs) for CO2 capturing in typical absorption/stripper process are considered. The use of ionic liquids is considered to be cost-effective because it requires less energy for solvent recovery compared to other conventional processes. A mathematical model is developed for the process based on Peng-Robinson (PR) equation of state (EoS) which is validated with experimental data for various solutions involving CO2. The model is utilized to study the sorbent and energy demand for three types of ILs at specific CO2 capturing rates. The energy demand is manifested by the vapor-liquid equilibrium temperature necessary to remove the captured CO2 from the used solvent in the regeneration step. It is found that higher recovery temperature is required for solvents with higher solubility coefficient. For all ILs, the temperature requirement is less than that required by the typical monoethanolamine (MEA) solvent. The effect of the CO2 loading in the sorbent stream on the process performance is also examined.

**Keywords:**
Ionic liquid,
CO2 capturing,
CO2 solubility,
Vaporliquid
equilibrium.

##### 10 Nonlinear Effects in Bubbly Liquid with Shock Waves

**Authors:**
Raisa Kh. Bolotnova,
Marat N. Galimzianov,
Andrey S. Topolnikov,
Uliana O. Agisheva,
Valeria A. Buzina

**Abstract:**

**Keywords:**
bubbly liquid,
cavitation,
equation of state,
shock
wave

##### 9 Simulation of Multiphase Flows Using a Modified Upwind-Splitting Scheme

**Authors:**
David J. Robbins,
R. Stewart Cant,
Lynn F. Gladden

**Abstract:**

A robust AUSM+ upwind discretisation scheme has been developed to simulate multiphase flow using consistent spatial discretisation schemes and a modified low-Mach number diffusion term. The impact of the selection of an interfacial pressure model has also been investigated. Three representative test cases have been simulated to evaluate the accuracy of the commonly-used stiffenedgas equation of state with respect to the IAPWS-IF97 equation of state for water. The algorithm demonstrates a combination of robustness and accuracy over a range of flow conditions, with the stiffened-gas equation tending to overestimate liquid temperature and density profiles.

**Keywords:**
Multiphase flow,
AUSM+ scheme,
liquid EOS,
low Mach number models

##### 8 Numerical Analysis on Rapid Decompression in Conventional Dry Gases using One- Dimensional Mathematical Modeling

**Authors:**
Evgeniy Burlutskiy

**Abstract:**

**Keywords:**
Mathematical model,
Rapid Gas Decompression

##### 7 Mathematical Modeling of Non-Isothermal Multi-Component Fluid Flow in Pipes Applying to Rapid Gas Decompression in Rich and Base Gases

**Authors:**
Evgeniy Burlutskiy

**Abstract:**

**Keywords:**
Mathematical model,
Multi-Component gas mixture
flow,
Rapid Gas Decompression

##### 6 Numerical Analysis of Rapid Gas Decompression in Pure Nitrogen using 1D and 3D Transient Mathematical Models of Gas Flow in Pipes

**Authors:**
Evgeniy Burlutskiy

**Abstract:**

**Keywords:**
Mathematical model,
Rapid Gas Decompression

##### 5 Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) Parameters for Propane, Ethylene, and Hydrogen under Supercritical Conditions

**Authors:**
Ilke Senol

**Abstract:**

Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) equation of state (EOS) is a modified SAFT EOS with three pure component specific parameters: segment number (m), diameter (σ) and energy (ε). These PC-SAFT parameters need to be determined for each component under the conditions of interest by fitting experimental data, such as vapor pressure, density or heat capacity. PC-SAFT parameters for propane, ethylene and hydrogen in supercritical region were successfully estimated by fitting experimental density data available in literature. The regressed PCSAFT parameters were compared with the literature values by means of estimating pure component density and calculating average absolute deviation between the estimated and experimental density values. PC-SAFT parameters available in literature especially for ethylene and hydrogen estimated density in supercritical region reasonably well. However, the regressed PC-SAFT parameters performed better in supercritical region than the PC-SAFT parameters from literature.

**Keywords:**
Equation of state,
perturbed-chain,
PC-SAFT,
super critical.

##### 4 Prediction of Henry's Constant in Polymer Solutions using the Peng-Robinson Equation of State

**Authors:**
Somayeh Tourani,
Alireza Behvandi

**Abstract:**

The peng-Robinson (PR), a cubic equation of state (EoS), is extended to polymers by using a single set of energy (A1, A2, A3) and co-volume (b) parameters per polymer fitted to experimental volume data. Excellent results for the volumetric behavior of the 11 polymer up to 2000 bar pressure are obtained. The EoS is applied to the correlation and prediction of Henry constants in polymer solutions comprising three polymer and many nonpolar and polar solvents, including supercritical gases. The correlation achieved with two adjustable parameter is satisfactory compared with the experimental data. As a result, the present work provides a simple and useful model for the prediction of Henry's constant for polymer containing systems including those containing polar, nonpolar and supercritical fluids.

**Keywords:**
Equation of state,
Henry's constant,
Peng-Robinson,
polymer solution.

##### 3 Modeling and Numerical Simulation of Sound Radiation by the Boundary Element Method

**Authors:**
Costa,
E.S.,
Borges,
E.N.M.,
Afonso,
M.M.

**Abstract:**

The modeling of sound radiation is of fundamental importance for understanding the propagation of acoustic waves and, consequently, develop mechanisms for reducing acoustic noise. The propagation of acoustic waves, are involved in various phenomena such as radiation, absorption, transmission and reflection. The radiation is studied through the linear equation of the acoustic wave that is obtained through the equation for the Conservation of Momentum, equation of State and Continuity. From these equations, is the Helmholtz differential equation that describes the problem of acoustic radiation. In this paper we obtained the solution of the Helmholtz differential equation for an infinite cylinder in a pulsating through free and homogeneous. The analytical solution is implemented and the results are compared with the literature. A numerical formulation for this problem is obtained using the Boundary Element Method (BEM). This method has great power for solving certain acoustical problems in open field, compared to differential methods. BEM reduces the size of the problem, thereby simplifying the input data to be worked and reducing the computational time used.

**Keywords:**
Acoustic radiation,
boundary element

##### 2 Removal of CO2 and H2S using Aqueous Alkanolamine Solusions

**Authors:**
Zare Aliabad,
H.,
Mirzaei,
S.

**Abstract:**

**Keywords:**
Absorber,
DEA,
MDEA,
Simulation.

##### 1 Group Contribution Parameters for Nonrandom Lattice Fluid Equation of State involving COSMO-RS

**Authors:**
Alexander Breitholz,
Wolfgang Arlt,
Ki-Pung Yoo

**Abstract:**

**Keywords:**
COSMO-RS,
Equation of State,
Group contribution,
Lattice Fluid,
Phase equilibria.