Search results for "fuel"

Controllable Solid Propellant Rocket Motor Stability: Deep and Rapid Variable Thrust Operations

2008

When flow and combustion processes couple with the acoustic modes of the combustion chamber, the solid rocket motors experience unsteady gas motion and associated thrust oscillation and motor vibration. The operations of the variable nozzle introduce relevant dynamic changes in the chamber flow and combustion. This article proposes a non-linear approach for the analysis of the effects of severe nozzle manoeuvres on the controllable solid rocket motor stability and provides the evidence that the acoustic wave amplitude evolution is influenced by the nozzle manoeuvre severity, shape and direction. The additional complexity in the problem of the combustion stability analysis introduced by the …

A Deep Insight into Different Acidic Additives as Doping Agents for Enhancing Proton Conductivity on Polybenzimidazole Membranes

2020

[EN] The use of phosphoric acid doped polybenzimidazole (PBI) membranes for fuel cell applications has been extensively studied in the past decades. In this article, we present a systematic study of the physicochemical properties and proton conductivity of PBI membranes doped with the commonly used phosphoric acid at different concentrations (0.1, 1, and 14 M), and with other alternative acids such as phytic acid (0.075 M) and phosphotungstic acid (HPW, 0.1 M). The use of these three acids was reflected in the formation of channels in the polymeric network as observed by cross-section SEM images. The acid doping enhanced proton conductivity of PBI membranes and, after doping, these conducti…

Phosphoric Acid Doped Polybenzimidazole (PBI)/Zeolitic Imidazolate Framework Composite Membranes with Significantly Enhanced Proton Conductivity unde…

2018

The preparation and characterization of composite polybenzimidazole (PBI) membranes containing zeolitic imidazolate framework 8 (ZIF-8) and zeolitic imidazolate framework 67 (ZIF-67) is reported. The phosphoric acid doped composite membranes display proton conductivity values that increase with increasing temperatures, maintaining their conductivity under anhydrous conditions. The addition of ZIF to the polymeric matrix enhances proton transport relative to the values observed for PBI and ZIFs alone. For example, the proton conductivity of PBI@ZIF-8 reaches 3.1 10&minus

Vehicles PEMFC Power System Mathematical Model for Integrated Design

2013

Surface Segregation Entropy of Protons and Oxygen Vacancies in BaZrO3

2016

The perovskite BaZrO3 has attracted considerable attention in the recent decade due to its high temperature proton conducting properties, and possible application as electrolyte in intermediate temperature fuel cells and electrolyzers. In this contribution, we performed, for the first time, first-principles calculations of the phonon contribution to the defect thermodynamics of the ZrO2 terminated (001) surface of BaZrO3. The approach allows us to determine both the segregation enthalpy and entropy of defects, which we apply to two fundamental defects in BaZrO3; fully charged oxygen vacancies (vO••) and protonic defects (OHO•). The calculations show that both defects exhibit favorable segre…

Load match and grid interaction optimization of a net zero energy building through electricity storage: An Italian case-study

2016

The study aims at applying of Load Match and Grid Interaction indexes to a Net Zero Energy Building in order to optimize the performances of its energy systems. The case study is a modular prefabricated house that uses solar energy (photovoltaic) and natural gas (Fuel Cell) as energy sources and equipped with an Energy Management System addressing the optimal energy use.

Slow Pyrolysis come metodo per la valorizzazione di rifiuti e biomassa residuale

2022

A Novel Lab‐Scale Fixed‐Bed Pyrolysis Reactor for Biofuel Production from Agro‐Waste: Experimental Set‐up and Preliminary Life Cycle Assessment Study

2020

The present study reports the features and set-up of a novel lab-scale fixed bed pyrolysis reactor for the production of solid and liquid bio-fuels from waste biomass. The fixed bed reactor is tested by carrying out pyrolysis experiments using two different waste biomasses. Olive tree trimmings (OT) and olive pulp (OP), olive cultivation and olive mill industries residues respectively, are pyrolyzed, under nitrogen atmosphere, between 200 and 650 °C for a residence time of 0.5 h. The OT and OP pyrolysis chars were characterized in terms of mass yields, high calorific values (HHVs), proximate and elemental analysis. Char mass yields, on a dry basis (d.b.), decreased from 91 to 23 wt% and fro…

Computer Simulation to Optimize the VFA Alpha Prototype with a Hydraulic Piston Compressor and an Integrated Booster

2020

The research has been supported by the European Regional Development Fund project "Competence Centre of Mechanical Engineering", contract No.1.2.1.1/18/A/008 signed between the Competence Centre of Mechanical Engineering and the Central Finance and Contracting Agency, Research No. 3.1 "Additional research and integra tion of the technology of hydraulic piston, aiming to develop and demonstrate economically efficient compressed natural gas smart commercial vehicle fuelling appliance". Our special gratitude to Gaspard Bouteau, PhD, Research Engineer, who conducted research in Engie Lab CRIGEN. Scientific co-authorship of the Laboratory of Materials for Energy Harvesting and Storage, ISSP UL h…

Feature selection strategies for quality screening of diesel samples by infrared spectrometry and linear discriminant analysis.

2012

Abstract A rapid approach has been developed for the characterization of diesel quality, based on attenuated total reflectance – Fourier transform infrared (ATR-FTIR) spectrometry, which could be useful for diagnosing the sample quality condition. As a supervised technique, linear discriminant analysis (LDA) was employed to process the spectrometric data. The role of variable selection methods was also evaluated. Successive projection algorithm (SPA) and genetic algorithm (GA) feature selection techniques were applied prior to the discriminative procedure. It was aimed to compare the effect of feature selection procedures on classification capability of IR spectrometry for the diesel sample…