scholarly journals Standard test case runs for the empulse monopole fieldsolver and conductivity generation model

1981 ◽  
Author(s):  
F.W. Chambers ◽  
D.M. Cox
Keyword(s):  
Standard Test ◽  
Test Case ◽  
Generation Model

scholarly journals Evaluation of a Scale-Resolving Methodology for the Multidimensional Simulation of GDI Sprays

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2699 ◽  
Author(s):  
Giovanni Di Ilio ◽  
Vesselin K. Krastev ◽  
Giacomo Falcucci
Keyword(s):  
Turbulence Modeling ◽  
Direct Injection ◽  
Test Procedure ◽  
Hybrid Approach ◽  
Development Trend ◽  
Standard Test ◽  
Gasoline Direct Injection ◽  
Model Parameters ◽  
Test Case ◽  
Passenger Cars

The introduction of new emissions tests in real driving conditions (Real Driving Emissions—RDE) as well as of improved harmonized laboratory tests (World Harmonised Light Vehicle Test Procedure—WLTP) is going to dramatically cut down NOx and particulate matter emissions for new car models that are intended to be fully Euro 6d compliant from 2020 onwards. Due to the technical challenges related to exhaust gases’ aftertreatment in small-size diesel engines, the current powertrain development trend for light passenger cars is shifted towards the application of different degrees of electrification to highly optimized gasoline direct injection (GDI) engines. As such, the importance of reliable multidimensional computational tools for GDI engine optimization is rapidly increasing. In the present paper, we assess a hybrid scale-resolving turbulence modeling technique for GDI fuel spray simulation, based on the Engine Combustion Network “Spray G” standard test case. Aspects such as the comparison with Reynolds-averaged methods and the sensitivity to the spray model parameters are discussed, and strengths and uncertainties of the analyzed hybrid approach are pointed out. The outcomes of this study serve as a basis for the evaluation of scale-resolving turbulence modeling options for the development of next-generation directly injected thermal engines.

A Generalized Axisymmetric Boundary Condition Method for Parallel Unstructured Field Solvers

2010 ◽  
Author(s):  
Daniel G. Hyams ◽  
Robert Webster ◽  
Kidambi Sreenivas
Keyword(s):  
Boundary Condition ◽  
Search Algorithm ◽  
Pressure Ratio ◽  
Standard Test ◽  
Test Case ◽  
Parallel Mechanisms ◽  
Client Data ◽  
Boundary Condition Method ◽  
Design Speed ◽  
Control Volumes

A generalized interpolative interface is developed to provide an axisymmetric boundary condition for multielement unstructured field solvers, including those that require highly stretched anisotropic meshes. The method centers around an extruded interpolative interface that does not require matched unstructured grids on the corresponding axisymmetric surfaces. Arc-based mesh extrusions are constructed from each periodic interface, which allow for closure and the solution of control volumes that lie on the interface. For each extruded point, a corresponding virtual point is created in order to control the exact location at which the client data interpolations are performed; for axisymmetric surfaces, the virtual points are rotated and placed inside of the opposite side of the domain. Special procedures, such as utilization of surface projections and parallel boundary layer displacement algorithms, are required for support of highly stretched anisotropic grids commonly used in the resolution of boundary layers in fluid flow solvers. All algorithms used to extrude the interpolative surface, place virtual points, and interpolate for the client data must be parallelized for compatibility with modern parallel field solvers. No restrictions are to be placed on the subdomain decomposition. To this end, fully general parallel mechanisms are implemented in order to transport data from its native storage to a possibly remote location. This overall axisymmetric boundary condition scheme is implemented in the Tenasi code for testing. Interpolation requires a parallel unstructured multielement search algorithm, which is a concerted effort by itself, and is the subject of an upcoming paper. This axisymmetric interface scheme is validated on an empty rotor passage, as well as on a Rotor 37 standard test case at full design speed. For these simulations, the two equation Menter SST [1] turbulence model is utilized. Profiles of the relative Mach number aft of the blade and pressure ratio data match very well with experimental results, demonstrating the validity of the proposed approach.

scholarly journals Simulations of Aeroelasticity in an Annular Cascade Using a Parallel 3-Dimensional Navier-Stokes Solver

2002 ◽  
Author(s):  
Ivan McBean ◽  
Feng Liu ◽  
Kerry Hourigan ◽  
Mark Thompson
Keyword(s):  
Unsteady Flow ◽  
Flow Model ◽  
Standard Test ◽  
Navier Stokes ◽  
Test Case ◽  
Turbine Cascade ◽  
3 Dimensional ◽  
Flow Through ◽  
The Stability ◽  
Annular Cascade

A parallel multi-block Navier-Stokes solver with the k-ω turbulence model is developed to simulate the 3-dimensional unsteady flow through an annular turbine cascade. Results at mid-span are compared with the experimental results of Standard Test Case 4. Comparisons are made between 3-dimensional and 2-dimensional, and inviscid and viscous simulations. The inclusion of a viscous flow model does not greatly affect the stability of the configuration.

Standard test case for a low-speed, turbulent junction vortex flow

AIAA Journal ◽  
1991 ◽  
Vol 29 (1) ◽  
pp. 14-15 ◽  
Author(s):  
F. J. Pierce
Keyword(s):  
Vortex Flow ◽  
Standard Test ◽  
Test Case ◽  
Low Speed

scholarly journals A standard test case suite for two-dimensional linear transport on the sphere: results from a collection of state-of-the-art schemes

2014 ◽  
Vol 7 (1) ◽  
pp. 105-145 ◽  
Author(s):  
P. H. Lauritzen ◽  
P. A. Ullrich ◽  
C. Jablonowski ◽  
P. A. Bosler ◽  
D. Calhoun ◽  
...  
Keyword(s):  
State Of The Art ◽  
Model Development ◽  
Finite Volume Methods ◽  
Standard Test ◽  
Ocean Modeling ◽  
Test Case ◽  
Linear Transport ◽  
Computing Platform ◽  
Wide Range ◽  
Cubed Sphere

Abstract. Recently, a standard test case suite for 2-D linear transport on the sphere was proposed to assess important aspects of accuracy in geophysical fluid dynamics with a "minimal" set of idealized model configurations/runs/diagnostics. Here we present results from 19 state-of-the-art transport scheme formulations based on finite-difference/finite-volume methods as well as emerging (in the context of atmospheric/oceanographic sciences) Galerkin methods. Discretization grids range from traditional regular latitude–longitude grids to more isotropic domain discretizations such as icosahedral and cubed-sphere tessellations of the sphere. The schemes are evaluated using a wide range of diagnostics in idealized flow environments. Accuracy is assessed in single- and two-tracer configurations using conventional error norms as well as novel diagnostics designed for climate and climate–chemistry applications. In addition, algorithmic considerations that may be important for computational efficiency are reported on. The latter is inevitably computing platform dependent. The ensemble of results from a wide variety of schemes presented here helps shed light on the ability of the test case suite diagnostics and flow settings to discriminate between algorithms and provide insights into accuracy in the context of global atmospheric/ocean modeling. A library of benchmark results is provided to facilitate scheme intercomparison and model development. Simple software and data sets are made available to facilitate the process of model evaluation and scheme intercomparison.

scholarly journals A standard test case suite for two-dimensional linear transport on the sphere: results from a collection of state-of-the-art schemes

2013 ◽  
Vol 6 (3) ◽  
pp. 4983-5076 ◽  
Author(s):  
P. H. Lauritzen ◽  
P. A. Ullrich ◽  
C. Jablonowski ◽  
P. A. Bosler ◽  
D. Calhoun ◽  
...  
Keyword(s):  
State Of The Art ◽  
Model Development ◽  
Finite Volume Methods ◽  
Standard Test ◽  
Ocean Modeling ◽  
Test Case ◽  
Linear Transport ◽  
Computing Platform ◽  
Wide Range ◽  
Cubed Sphere

Abstract. Recently, a standard test case suite for 2-D linear transport on the sphere was proposed to assess important aspects of accuracy in geophysical fluid dynamics with a "minimal" set of idealized model configurations/runs/diagnostics. Here we present results from 19 state-of-the-art transport scheme formulations based on finite-difference/finite-volume methods as well as emerging (in the context of atmospheric/oceanographic sciences) Galerkin methods. Discretization grids range from traditional regular latitude-longitude grids to more isotropic domain discretizations such as icosahedral and cubed-sphere tessellations of the sphere. The schemes are evaluated using a wide range of diagnostics in idealized flow environments. Accuracy is assessed in single- and two-tracer configurations using conventional error norms as well as novel diagnostics designed for climate and climate-chemistry applications. In addition, algorithmic considerations that may be important for computational efficiency are reported on. The latter is inevitably computing platform dependent, The ensemble of results from a wide variety of schemes presented here helps shed light on the ability of the test case suite diagnostics and flow settings to discriminate between algorithms and provide insights into accuracy in the context of global atmospheric/ocean modeling. A library of benchmark results is provided to facilitate scheme intercomparison and model development. Simple software and data-sets are made available to facilitate the process of model evaluation and scheme intercomparison.

scholarly journals Supplier side optimal bidding strategy for electricity market using bacterial foraging optimization algorithm

2021 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Uday Sriram L ◽  
Siva Naga Raju ◽  
Chandram Karri
Keyword(s):  
Electricity Market ◽  
Unit Commitment ◽  
Standard Test ◽  
Bidding Strategy ◽  
Test Case ◽  
Bacterial Foraging Optimization ◽  
Bacterial Foraging ◽  
Single Side ◽  
Prime Objective ◽  
Optimal Bidding

<p class="Title1">In this article, bacterial foraging optimization (BFO) algorithm is developed for single side optimal bidding strategy in an electricity market. Optimal bidding strategy is one of the important functions in the electricity market along with forecasting of the electricity price and the profit based unit commitment. The prime objective of generating company (Genco) is to maximize their profit when they participate in the bidding process. The BFO algorithm has been used to maximize the probability density function (pdf). In the second stage the BFO algorithm is again applied to maximize the profit of the suppliers. The Proposed algorithm is developed in MATLAB (Version, 2019) and tested on standard test case available in the literature. Also, the simulation results are presented and compared. It is noticed that the proposed method yields the best results in terms of profit.</p>

Probabilistic and deterministic analysis of single diode model of a solar cell: a case study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akshit Samadhiya ◽  
Kumari Namrata
Keyword(s):  
Solar Cell ◽  
Objective Function ◽  
Surface Defects ◽  
Parametric Uncertainty ◽  
Monte Carlo Sampling ◽  
Standard Test ◽  
Test Case ◽  
Electrical Parameters ◽  
Deterministic Analysis ◽  
Set Of Points

Abstract The paper presents a probabilistic and deterministic analysis for parameterization of solar cells to study the electrical behavior based on single diode model. Estimation of electrical parameters is important in design, control, and delivery of solar power through a solar cell. Due to non-linearity and non-convexity of the parameterization problem, the single objective function is transformed into set of sub-problems through Pascoletti–Serafini Scalarization using ε -constraint method. Thus, each sub-problem is minimized to obtain a unique set of points on Pareto front. The results are compared with multi-variable Newton Raphson (NR), Particle Swarm Optimization (PSO), and Black Widow Optimization (BWO) based on convergence accuracy, precision and ability to trace non-convex region. Solarex MSX83 (36 cells) is considered as the test case for the validation of deterministic optimization models under Standard test Conditions (STCs). Electrical characteristics are plotted under STC (1000 W/m2, 1.5 A.M. spectrum, 25 °C) which shows fair agreement with the actual experimental curves present in the datasheet. The results obtained from the proposed bi-objective minimization algorithm shows a better convergence response with an additional benefit of tracing the convexity of the problem. Moreover, the proposed technique also ensures a good fit as suggested by the statistical means. Finally, a probabilistic model is proposed for single diode model of a solar cell in the presence of parametric uncertainty. Random samples of uncertain electrical parameters are obtained using Latin hypercube and Monte Carlo sampling methods to estimate the probability of the output response. It can be concluded that the objective function shows a bi-modal distribution under parametric variations which may arise due to measurement error, shading losses, surface defects, and manufacturing issues.

CO Prediction in LES of Turbulent Flames With Additional Modeling of the Chemical Source Term

2012 ◽  
Author(s):  
Anja Ketelheun ◽  
Kai Aschmoneit ◽  
Johannes Janicka
Keyword(s):  
Combustion Products ◽  
Standard Test ◽  
Turbulent Flames ◽  
Test Case ◽  
Eddy Simulation ◽  
Tabulated Chemistry ◽  
Wide Range ◽  
Large Eddy ◽  
Combustion Processes ◽  
Fast Chemical

The prediction of combustion processes using Large Eddy Simulation (LES) combined with tabulated chemistry has proven to be very successful and become very popular during the last years in both academia and industry. Technical combustion systems feature a wide range of time and length scales which need to be resolved. The LES describes the rather slow, but turbulent and unsteady flow field very well, while the fast chemical reactions can be represented by tabulated chemistry models like Flamelet Generated Manifolds. Pollutants, being only present at lower concentrations and developing slowly are not easy to capture with the standard manifold defined by the fast major combustion products. Therefore, additional modeling in order to predict the carbon monoxide emissions is presented in this paper. The choice of the reaction progress variable and the solution of an additional transport equation with and without extra modeling for the post flame zone was investigated. These models are applied to a standard test case and compared to experimental data and the standard tabulation approach.

scholarly journals A Scale-Aware Anticipated Potential Vorticity Method: On Variable-Resolution Meshes

2012 ◽  
Vol 140 (9) ◽  
pp. 3127-3133 ◽  
Author(s):  
Qingshan Chen ◽  
Max Gunzburger ◽  
Todd Ringler
Keyword(s):  
Potential Vorticity ◽  
Numerical Experiments ◽  
Unstructured Grids ◽  
Optimal Parameter ◽  
Standard Test ◽  
Test Case ◽  
Original Formulation ◽  
Variable Resolution ◽  
Optimal Values ◽  
New Formulation

Abstract A scale-aware formulation of the anticipated potential vorticity method (APVM), previously derived for quasi-uniform unstructured grids, is evaluated on multiresolution grids. Comparison is made to the original, nonscale-aware formulation of the APVM. Numerical experiments are performed using the shallow-water standard test case 5. The scale awareness of the new formulation is demonstrated by the following observations: (i) the range of optimal values for the single parameter of the new formulation is much less sensitive to grid resolution than that of the original formulation; (ii) within the optimal parameter range, the new formulation is able to maintain proper dissipation across scales and is thus able to produce better results in terms of errors in the potential enstrophy spectrum curves; and (iii) the new formulation is robust in that a single optimal parameter obtained for a specific grid can be safely used on other grids as well.

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