Simulation Software Tools Research Articles

A Tool for Industrial Verification and Benchmarking of FDD/FTC Designs

The RECONFIGURE Functional Engineering Simulator (FES) is a simulation software tool based on the MATLAB°/Simulink° modeling & simulation environment, specifically designed to support the industrial verification and benchmarking of the Fault Detection and Diagnosis (FDD) and Fault Tolerant Control (FTC) algorithm prototypes designed by the partners of the RECONFIGURE project. The FES includes the benchmark scenarios defined by Airbus for the evaluation of the FDD/FTC designs, namely sensor faults, actuator faults and icing conditions. Although based on a reusable generic-purpose simulation infrastructure layer, the FES has been customized for the verification campaign to be executed with the Airbus benchmark model. Although the development of the FES has not concluded at the time of writing this article, we can describe the software architecture, design and simulation capabilities of this tool within the context of an industrial verification & validation process.

KivaTM: a numerical framework for improving foundation heat transfer calculations

KivaTM was developed to evaluate the energy performance of building foundation designs. This free, open-source tool can be integrated into existing annual building energy simulation software tools. This article describes the verification of Kiva's six numerical solution methods against the International Energy Agency Building Energy Simulation Test and Diagnostic Method test cases for slab-on-grade heat conduction. Comparisons of accuracy, computation time and stability between the numerical solution methods revealed their advantages and disadvantages. While each solution method satisfactorily approximates slab heat loss, many methods exhibited stability issues or required substantially longer computation time. The method least affected by these two challenges was the alternating-direction implicit (ADI) method. Kiva features four approaches of initializing the soil temperatures for an annual simulation. A new accelerated initialization approach is shown to reduce the required years of pre-simulation. The combination of the ADI method and accelerated initialization reduces the total computation time by 95% relative to the traditional implicit solutions.

Design of a novel dual: band planar inverted F - antenna for mobile radio applications

The design of a novel compact dual band PIFA (Planar Inverted F-Antenna) as an embedded antenna is reported in this paper for mobile radio applications. The new shorted planar antenna is realized using copper sheet of thickness 1mm and air as the dielectric substrate. The radiating patch consists of a branch line slit to reduce the size of the antenna having a ground size of 36 x 80 mm2. It can be used in internal mobile antennas for applications in GSM band, GCV (1.85 - 1.99GHz), PCS - 1900, IMT-2000 and UMTS 2100 networks. The simulations are done using the Ansoft High Frequency Structure Simulator (HFSS) software tool. The two operating frequency ranges obtained have good matching and radiation characteristics. The simulated results are well supported by measured results of the prototype of the antenna fabricated.

Rapid, robust, distributed evaluation and control of train scheduling on a single line track

The technology for controlling the distance between two trains is shifting from traditional fixed red, yellow and green signals on the infrastructure track circuits towards more and more dynamic systems, which are based on moving blocks, where the distance is computed according to real-time positioning, and the control of the distance is computed on-line. This is the case, for example, in the European Rail Traffic Management System (ERTMS), which proposes three different levels, from 1 to 3. This paper addresses the time-honoured problem of scheduling trains on a single track, in the light of recent results in robust team decision theory. The control model can be used in two modes: as a decision support tool for train dispatchers to evaluate the distance between trains in the current schedule, and as a planning tool to evaluate the effects of timetable changes. The main contribution of the paper is the application of a recent result in robust team decision theory to control noncritical train distances in moving blocks, such as in ERTMS Level 3. The case study is related to real data from an ERTMS simulation and controller software tool.

Comparison Between Two Hydrodynamic Models for Flooding Simulations at River Lima Basin

According to EU flood risks directive, flood hazard maps should include information on hydraulic characteristics of vulnerable locations, i.e. the inundated areas, water depths and velocities. These features can be assessed by the use of advanced hydraulic modelling tools which are presented in this paper based on a case study in the river Lima basin, Portugal. This river includes several flood-prone areas. Ponte Lima town is one of the places of higher flood risk. The upstream dams can lower the flood risks if part of its storage capacity is allocated for mitigating flood events. However, proper management of dam releases and the evaluation of downstream river flows should be considered for preventing flood damages. A hydrological and a one-dimensional hydrodynamic model were implemented, and at a particular flood-prone town, inundation was assessed using a two-dimensional model. The hydrological model is based on the well known Sacramento model. For this purpose, two different modelling implementations were analysed: a model based on a finite element mesh and a model based on rectangular grids. The computational performance of the two modelling implementations is evaluated. Historical flood events were used for model calibration serving as a basis for the establishment of different potential flood scenarios. Intense precipitation events in the river’s basin and operational dam releases are determinant for the occurrence of floods at vulnerable downstream locations. The inundation model based on the unstructured mesh reveals to be more computationally efficient if high spatial resolution is required. A new combination of software tools for floods simulation is presented including an efficient alternative for simulation of 2-D inundation using a finite element mesh instead of a grid.

업무용 건물의 지열 히트펌프 시스템에 대한 성능 예측

Ground-source heat pump (GSHP) systems have become an efficient alternative to conventional cooling and heating methods due to their higher energy efficiency. These systems use the ground as a heat source and the heat sink for cooling mode operation. The purpose of this simulation study is to evaluate the performance of a hypothetical GSHP system in an office building and to assess the energy saving effect against the existing HVAC systems (boiler and turbo chiller). We collected monthly energy consumption data from an actual office building (32,488 m 2 ) in Seoul, and created a model to calculate the hourly building loads with EnergyPlus. In addition, we used GLD (Ground Loop Design) V8.0, a GSHP system design and simulation software tool, to evaluate hourly and monthly performance of the GSHP system. The energy consumption for the GSHP system based on the hourly simulation results were estimated to be 582.6 MWh/year for cooling and 593.2 MWh/year for heating, while those for the existing HVAC systems were found to be 674.5 MWh/year and 2,496.4 MWh/year, respectively. The seasonal performance factor (SPF) of the GSHP system was also calculated to be in the range of 3.37∼4.28.

High-permeability FILMTEC™ SEAMAXX™ reverse osmosis elements: a success story in the Canary Islands

Reverse osmosis (RO) has developed into one of the most commonly applied technologies for the reduction of the salt content of a feed stream. While it is a widely applied purification process, the market is continuously challenging suppliers for innovation to increase the economics and sustainability. This paper will review and analyse the field performance of Dow FILMTEC™ new high-flow/low-energy seawater reverse osmosis elements—SEAMAXX™. This new seawater RO membrane, which has the highest permeability currently available, is based on innovation related to membrane chemistry. SEAMAXX can be used to increase the recovery of an existing system or to decrease the energy consumption. In either case, the final cost of water is estimated to be between 10 and 15% lower compared to previously available state of the art RO elements. This paper will focus on three different cases studies where the expected performance of SEAMAXX has been validated. Two of these cases correspond to small-size and medium-size pilot trials completed at the Water Technology Center of Dow Water and Process Solutions in Tarragona, Spain. The third experience is a commercial installation which has been in operation with SEAMAXX elements since May 2013. In this particular facility, a retrofit of the RO system was undertaken such that existing 11-year-old FILMTEC membranes were replaced with next generation SWRO membranes. This commercial installation, located in the Canary Islands (Spain) treats the seawater (Atlantic Ocean) well to produce drinking water. In this third case, the performance of the desalination plant will be compared with the performance of the previous elements as well as with the predicted or expected performance of SEAMAXX according to ROSA™ (reverse osmosis system analysis) simulation software and DOW™ FT-NORM normalization tool. Rejection of dissolved salts and in particular, rejection of Boron has been carefully monitored by regular analysis in Dow’s R&D Lab and in external certified laboratories. After almost one year in operation, the performance of SEAMAXX has been validated through different seasons and different sets of operating conditions, confirming the expected savings in energy consumption.

Методика управления выживанием и развитием малых предприятий на основе использования инноваций

The article as an economic entity is considered a small business (SB), as one of the most important links that can ensure economic growth, based on international experience. Due to the high mobility of the SB can quickly readjust depending on the current situation in the country and in the world markets. A generalized version of the technology analysis of the current economic condition of the SB, its environment and management decisions on innovation development. The technique is structured and presented in the form of six stages of action that should be taken of (SB) in order to achieve the current tactical and strategic objectives. Tools for the implementation of the proposed technique can be advanced analytical and simulation software tools, both general and special purpose.

Energy and indoor air quality implications of alternative minimum ventilation rates in California offices

The energy and IAQ implications of varying prescribed minimum outdoor air ventilation rates (VRs) in California office buildings were estimated using the EnergyPlus building simulation software tool. Weighting factors were used to scale these model predictions to state wide estimates. Energy use predictions were then verified using surveyed California building energy end use data.Models predicted state wide office electricity use that was within 15% of reported electricity consumption from power utilities. The HVAC energy penalty of providing the current Title-24 VRs was approximately 6%, of the total HVAC energy use. Having economizers installed reduced average indoor formaldehyde exposure by 38% and lowered HVAC EUI by 20%. For California offices with economizers, 50% and 100% increases in Title-24 prescribed minimum VRs increased heating, ventilating, and air conditioning (HVAC) modeled energy use by 7.6% and 21.6%, respectively, while decreasing the annual average workplace formaldehyde exposure by 8.6% and 14.4%, respectively. Economizers increased VRs above the minimum 79% of the time lowering annual average concentrations of formaldehyde. Decreasing minimum VRs below the Title-24 rate would have smaller predicted effects on energy use and comparatively larger effects on formaldehyde concentrations. In buildings without economizers in many climate zones, increasing VRs up to 150% of the current Title-24 minimum would save HVAC energy and significantly reduce formaldehyde.A key conclusion is that raising future minimum VRs in California offices is unlikely to significantly improve time-averaged IAQ in buildings with economizers. Lowering future minimum VRs would be unlikely to deliver substantive energy savings.

Survey and comparative study of free simulation software for mobile robots

SUMMARYIn robotics, simulation has become an essential tool for research, education, and design purposes. Various software tools for mobile robot simulation have been developed and have reached different levels of maturity in recent years. This paper presents a general survey of mobile robot simulation tools and discusses qualitative and quantitative aspects of selection of four major simulators publicly available at no cost: Carmen, Player-Stage-Gazebo, Open Dynamics Engine, and Microsoft Robotics Developer Studio. The comparison of the simulators is aimed at establishing the range of applications for which these are best suited as well as their accuracy for certain simulation tasks. The simulators chosen for detailed comparison were selected considering their level of maturity, modularity, and popularity among engineers and researchers. The qualitative comparison included a discussion of relevant features. The quantitative analysis entailed the development of a detailed dynamical model of a mobile robot on a road with varying slope. This model was used as benchmark to compare the accuracy of each simulator. The validity of the simulated results was also contrasted against measurements obtained from experiments with a real robot. This research and analysis should be very valuable to educators, engineers, and researchers who are always seeking adequate tools for simulating autonomous mobile robots.

Closure to Discussion on “Distribution Locational Marginal Pricing for Optimal Electric Vehicle Charging Management”

AC optimal power flow (ACOPF) is typically used for operational dispatch decisions. However, DC optimal power flow (DCOPF) based on linearization of the ACOPF is widely used for locational marginal price (LMP) calculation in market operation and settlements due to its efficiency and reasonable accuracy. The DCOPF is considered to be sufficient in many cases. Especially for calculating LMPs of distribution systems, the DCOPF is a good option considering the large number of nodes in distribution systems. In industry, DCOPF has been employed by several software tools for chronological LMP simulation and forecasting.

Modelling and simulation of gyrotrons for ITER

Powerful gyrotrons of the megawatt class will be used for electron cyclotron resonance heating (ECRH) and current drive (ECCD) of magnetically confined plasma in the thermonuclear reactor ITER. For computer-aided design (CAD), analysis and optimization of their performance numerical experiments based on adequate physical models are used. In this paper, we outline and illustrate the current status of both the available software tools for numerical simulation of such gyrotrons, as well as the novel computer codes of the problem oriented GYREOSS software package which is under development now.

The PLATO Simulator: modelling of high-precision high-cadence space-based imaging

Many aspects of the design trade-off of a space-based instrument and its performance can best be tackled through simulations of the expected observations. The complex interplay of various noise sources in the course of the observations make such simulations an indispensable part of the assessment and design study of any space-based mission. We present a formalism to model and simulate photometric time series of CCD images by including models of the CCD and its electronics, the telescope optics, the stellar field, the jitter movements of the spacecraft, and all important natural noise sources. This formalism has been implemented in a versatile end-to-end simulation software tool, called PLATO Simulator, specifically designed for the PLATO space mission to be operated from L2, but easily adaptable to similar types of missions. We provide a detailed description of several noise sources and discuss their properties, in connection with the optical design, the allowable level of jitter, the quantum efficiency of the detectors, etc. The expected overall noise budget of generated light curves is computed as a function of the stellar magnitude, for different sets of input parameters describing the instrument properties. The simulator is offered to the scientific community for future use.

Simulation of Gradostat Using FMI (Functional Mock-up Interface) Standard

System simulations are used for modeling real dynamical processes that can be expressed in terms of ordinary differential equations, differential algebraic equations and discrete event simulation. There are many system simulation software tools and nearly all of them are suitable for modeling and simulation of gradostats. Most of them also support the FMI (Functional Mock-up Interface) standard for model exchange between them which gives us an opportunity to create much more reusable simulation softwares. In this paper we demonstrate how to model and run system simulations of gradostat model using FMI standard.

A fast algorithm for 3D simulation of thermal stratification in containment pools of nuclear power plants

Safety analysis is of ultimate importance for the operation of Nuclear Power Plants (NPP). Experiments even on a pilot scale are quite expensive and therefore numerical simulations play a major role in this analysis. They allow to predict the behaviour of NPP systems under different operational and accident conditions and to develop proper action plans for minimizing the risks of accidents, and minimizing the consequences of possible accidents. For a proper risk assessment and development of emergency plans, a very large number of scenarios have to be simulated, achieving acceptable accuracy for the critical parameters, such as radioactive pollution and temperature. The existing software tools are either very simplistic and therefore quite inaccurate or they use general CFD codes that makes them very slow. This paper presents a customized algorithm and corresponding software tools for simulation of non-isothermal flows in the containment pool of a NPP. It first summarizes the requirements for such simulation tools and then presents the new algorithm which, in the opinion of the authors, is a proper compromise between accuracy and efficiency for solving such problems. It uses a Fictitious Domain Method (FDM) to impose the boundary conditions, a Cartesian finite volume discretization combined with a Domain Decomposition (DD) technique, and a factorized perturbation of the incompressibility constraint proposed recently in Guermond and Minev (2010). Finally, results from numerical simulations in idealized and realistic geometries are presented and discussed.

On Different Approaches to Combine Cable Information Into Near-Field Data for Radiated-Field Estimation

Near-field scanning is often used to solve electromagnetic compatibility (EMC) problems. Aside from the purpose of visualization of near fields, measured near-field data can be used to estimate radiated fields. One of many challenges associated with using near-field to far-field transform technique for EMC application is the handling of attached cables. The objective of this investigation is to evaluate different methods to add cable information to the near-field data for radiated-field estimation. The investigation is carried out using numerical experiments in EMCoS EMC Studio, which is a commercial software tool for EM simulation providing method-of-moments solver. Measurement results from a specially designed test structure are presented to validate the simulation results.

Consideration of Envelope Airtightness in Modelling Commercial Building Energy Consumption

As strategies for improving building envelope and HVAC equipment efficiencies are increasingly required to reduce building energy use, a greater percentage of energy loss will occur through building envelope leakage. Although the energy impacts of unintended infiltration on a building’s energy use can be significant, current energy simulation software and design methods are generally not able to accurately account for envelope infiltration and the impacts of improved airtightness. The airflow analyses capabilities of several energy simulation software tools are summarized, including whether the program calculates airflow rates for the user or accepts them as inputs. The bases of these airflow rate estimation approaches are evaluated for their physical soundness and accuracy. A new strategy to more accurately incorporate airflow calculations into energy software is also proposed, which is based on relationships between building infiltration rates calculated using detailed multizone airflow models and building characteristics, weather conditions, and building envelope airtightness.

Transport Control Protocol for Cognitive Radio Ad Hoc Networks

The rapid demand for wireless communication networks in the last few decades has lead to spectrum scarcity, Hence there is need of efficient spectrum utilization is occurs. Cognitive radio is a novel technology which improve the spectrum resource utilization and allows a cognitive radio transceiver to detect and sense the available spectrum. Cognitive Radio (CR) networks allow users to transmit in the licensed spectrum bands, without degrading the performance of the Primary Users (PUs). Routing in CRN is a challenging task due to the variations in spectrum availability with time and periodic spectrum sensing undertaken by the CR users. In this paper we investigate the effect of TCP in CR ad hoc network environment and proposes multipath routing protocol, that uses on-demand distance vector routing, called Ad hoc On-demand Multipath Distance Vector (AOMDV) Routing Protocol. We analyze its performance using Network simulator (NS-2) software tool. Simulation gives effective result of cognitive radio ad hoc networks and analyzed the parameter delay, throughput and energy.

An economic analysis of Cyprus’ residential buildings’ energy retrofits potential

Cyprus’ building stock energy saving potential is considerably high due to the absence of legislation and regulations governing the energy performance of buildings, prior to the country's accession to the European Union. In this study, a methodology is proposed and applied to a typical residential building to assess the financial attractiveness of alternative retrofit scenarios. An advanced simulation software tool is utilised to measure the energy performance of a typical residential building in terms of envelope characteristics, construction materials and Heating, Ventilation and Air Conditioning system. The thermal model is used to assess the impact of alternative retrofitting scenarios. Then, an economic model is developed to evaluate the financial impact over the investment horizon. Finally, a risk analysis is conducted to investigate the stochastic behaviour of key input variables.

Design and Effects of Symmetrical Slotted Array on Microstrip Ultra wide Band Antenna

The given paper presents an Ultra Wide Band (UWB) which is simplified and compacted on a rectangular micro strip patch. The micro strip patch of rectangular shape has been narrowed at the bottom and the ground plane in cut-shorted at the top center. The substrate is FR4 substrate with the dimension of (28x29x1.6) mm and permittivity of 4.4. The antenna has been designed on HFSS v11.0 software simulation tool. The simulated results are shown in this paper. The designed antenna exhibits an impedance bandwidth between 3.3-16.9 GHz (for S11<-10 dB). The designed antenna has stable VSWR (1.0-2.0) and stable E and H plane over the given bandwidth range. The designed UWB antenna resonates at 6 different frequencies (at 3.9GHz, 6.5 GHz, 3.9GHz, 8.5 GHz, 11.2 GHz, 14.3GHz and 15.3GHz).. The Ultra wide bandwidth has been achieved by implementing the concept of frequency independence method. The antenna exhibits better UWB characteristics suitable for UWB applications. Keywords:Bandwidth,FCC, Group delay, Omni-directional, UWB, VSWR.