46 research outputs found
Performance Comparison of MATLAB and Neuro Solution Software on Estimation of Fuel Economy by Using Artificial Neural Network
In the world, scientific studies increase day by day and computer programs facilitate the human’s life.
Scientists examine the human’s brain’s neural structure and they try to be model in the computer and they give
the name of artificial neural network. For this reason, they think to develop more complex problem’s solution. The
purpose of this study is to estimate fuel economy of an automobile engine by using artificial neural network (ANN)
algorithm. Engine characteristics were simulated by using “Neuro Solution” software. The same data is used in
MATLAB to compare the performance of MATLAB is such a problem and show its validity. The cylinder,
displacement, power, weight, acceleration and vehicle production year are used as input data and miles per
gallon (MPG) are used as target data. An Artificial Neural Network model was developed and 70% of data were
used as training data, 15% of data were used as testing data and 15% of data is used as validation data. In
creating our model, proper neuron number is carefully selected to increase the speed of the network. Since the
problem has a nonlinear structure, multi layer are used in our model
Combustion of Fuel Surrogates:An application to gas turbine engines
The previously developed approaches for fuel droplet heating and evaporation processes, mainly using the Discrete Multi Component Model (DMCM), are investigated for the aerodynamic combustion simulation. The models have been recently improved and generalised for a broad range of bio-fossil fuel blends so that the application areas are broadened with an increased accuracy. The main distinctive features of these models are that they consider the impacts of species’ thermal conductivities and diffusivities within the droplets in order to account for the temperature gradient, transient diffusion of species and recirculation. A formulation of fuel surrogates is made using the recently introduced model, referred to as “Complex Fuel Surrogate Model (CFSM)”, and analysing their heating, evaporation and combustion characteristics. The CFSM is aimed to reduce the full composition of fuel to a much smaller number of components based on their mass fractions, and to formulate fuel surrogates. Such an approach has provided a proof of concept with the implementation of the developed model into a commercial CFD code ANSYS Fluent. A case study is made for the CFD modelling of a gas turbine engine using a kerosene fuel surrogate, which is the first of its kind. The surrogate is proposed using the CFSM, with the aim to reduce the computational time and improve the simulation accuracy of the CFD model
Designing a New Bell-Type Primary Air Nozzle for a Large-Scale Circulating Fluidized Bed Boilers
Performance of a homogeneous charge compression ignition engine fuelled with gasoline
The performance of a Homogeneous Charge Compression Ignition (HCCI) engine fuelled with gasoline by means of a stochastic reactor model is investigated. A zero-dimensional simulation code called Stochastic Reactor Model (SRM) for combustion and convective heat transfer is applied. The gasoline fuel was simulated with a Primary Reference Fuel (PRF) mechanism consisting of 157 species and 1552 reactions. Simulated results are compared with experimental measurements obtained using a Ricardo Hydra HCCI engine. Emissions of CO, CO2 and NOx as a function of the crank angle are considered. In addition, the dependence of performance and emissions on the temperature is investigated. Good qualitative agreement is found between the computations and the available experimental data. The performed numerical simulations predict the same trends; however, quantitative agreement is not very good because the shape of the real piston cannot be modelled in 0-D simulations
Hexadecane mechanisms: Comparison of hand-generated and automatically generated with pathways
In this paper, the automatically generated mechanism for hexadecane with both high and low temperature chemistry included is compared to a systematically generated mechanism by hand. In contrast to other systems for automatic generation, the REACTION system uses pathways to organize the application of reaction classes. A pathway is a sequence of reaction classes where only those species produced by the previous step of the pathway are used in the current step of the pathway. This "controlled" generation process not only mimics what is done by hand, but also helps to limit the size of the generated mechanisms. Both systematic reaction by reaction comparisons and numerical simulation (zero-dimensional constant volume) comparisons were done and the mechanisms were found to have minor differences. Both mechanisms used the same set of reaction classes to model the high and low temperature combustion chemistry of all n-alkanes up to hexadecane. In addition, a sensitivity analysis of all the reaction classes was performed. The generated mechanism has 2176 species and 7269 (reversible) reactions. (C) 2013 Elsevier Ltd. All rights reserved
Critical evaluation of CFD codes for interfacial simulation of bubble-train flow in a narrow channel
Computational fluid dynamics (CFD) codes that are able to describe in detail the dynamic evolution of the deformable interface in gas-liquid or liquid-liquid flows may be a valuable tool to explore the potential of multi-fluid flow in narrow channels for process intensification. In the present paper, a computational exercise for co-current bubble-train flow in a square vertical mini-channel is performed to investigate the performance of well-known CFD codes for this type of flows. The computations are based on the volume-of-fluid method (VOF) where the transport equation for the liquid volumetric fraction is solved either by the methods involving a geometrical reconstruction of the interface or by the methods that use higher-order difference schemes instead. The codes contributing to the present code-to-code comparison are an in-house code and the commercial CFD packages CFX, FLUENT and STAR-CD. Results are presented for two basic cases. In the first one, the flow is driven by buoyancy only, while in the second case the flow is additionally forced by an external pressure gradient. The results of the code-to-code comparison show that only the VOF method with interface reconstruction leads to physically sound and consistent results, whereas the use of difference schemes for the volume fraction equation shows some deficiencies. Copyright (C) 2007 John Wiley & Sons, Ltd
Sustainable energy production and consumption in Turkey: A review
In this century, energy has been the driving force of the global economy and it will, for sure, continue to be one of the most important element for the sustainable socio-economic development for the coming centuries. Therefore, energy producers and governors have a vital duty to provide enough energy in good quality continuously with low cost for the sustainable development. The subject of energy production and energy politics in Turkey generally comes at first privilege. Ahead of the 21st century, Turkish energy diplomacy started to affect the future course of Turkey's relations with the Eurasian countries as well as the Western countries. This paper describes energy production and consumption strategies in Turkey and criticizes Turkish energy policies. If the present pattern of energy production and consumption in Turkey is maintained, there will be serious problems to meet future energy demands due to shortages of resources and low financial inputs, combined with the environmental care for the country. As a result, major components of Turkey's strategy for sustainable development should include changing the present energy production and consumption patterns, expanding energy sources and the structure of power production, and creating an energy structure that is less or not at all risky to the environment. (C) 2008 Elsevier Ltd. All rights reserved