New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study

Several studies have aimed to convert diesel engines to dual- or tri-fuel engines to improve their fuel economy and reduce the emissions from diesel engine, however, most of these studies do not consider enhancing the homogeneity of fuel mixtures inside the engine and accurately controlling the air...

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Main Authors: Hussein A. Mahmood, Nor Mariah. Adam, B. B. Sahari, S. U. Masuri
Format: Article
Language:English
Published: MDPI AG 2017-09-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/10/9/1373
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author Hussein A. Mahmood
Nor Mariah. Adam
B. B. Sahari
S. U. Masuri
author_facet Hussein A. Mahmood
Nor Mariah. Adam
B. B. Sahari
S. U. Masuri
author_sort Hussein A. Mahmood
collection DOAJ
description Several studies have aimed to convert diesel engines to dual- or tri-fuel engines to improve their fuel economy and reduce the emissions from diesel engine, however, most of these studies do not consider enhancing the homogeneity of fuel mixtures inside the engine and accurately controlling the air fuel ratio. In this study, a new air-fuel mixer was designed, manufactured and tested. The proposed air-gaseous fuel mixer design was conceived to be suitable for mixing air with compressed natural gas (CNG) and a blend of hydrogen and compressed natural gas (HCNG) that gives homogenous mixtures with high uniformity index and also to be easily connected with an Electronic Control Unit (ECU) for controlling accurately the air-gaseous fuel ratio for different engine speeds. For optimizing the homogeneity inside the new mixer, fourteen different mixer models were created to investigate the effects of diameter, location, and the number of holes inside the mixer on the homogeneity and distribution of the mixtures. Computational fluid dynamics analysis software was used to check the flow behavior, distribution and homogeneity of mixtures inside the new mixer models. The simulation results revealed that the best uniformity index (UI) values are obtained in model 7 where the UI values are 0.939 and 0.937, respectively, for an air fuel ratio for a blend of hydrogen and compressed natural gas (AFRHCNG) = 51.31 and the air fuel ratio for compressed natural gas (AFRCNG) = 34.15. According to the numerical and experimental results for the new mixer (model 7) under different engine speeds (1000–4000) and air-CNG ratio of 34.15, a meaningful agreement is reached between the experimental and numerical values for AFRCNG (coefficient of determination (R2) = 0.96 and coefficient of variation (CoV) = 0.001494).
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spelling doaj.art-69ed789e86574befbbe556d9cf9077a42022-12-22T04:23:06ZengMDPI AGEnergies1996-10732017-09-01109137310.3390/en10091373en10091373New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical StudyHussein A. Mahmood0Nor Mariah. Adam1B. B. Sahari2S. U. Masuri3Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, MalaysiaDepartment of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, MalaysiaDepartment of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, MalaysiaDepartment of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, MalaysiaSeveral studies have aimed to convert diesel engines to dual- or tri-fuel engines to improve their fuel economy and reduce the emissions from diesel engine, however, most of these studies do not consider enhancing the homogeneity of fuel mixtures inside the engine and accurately controlling the air fuel ratio. In this study, a new air-fuel mixer was designed, manufactured and tested. The proposed air-gaseous fuel mixer design was conceived to be suitable for mixing air with compressed natural gas (CNG) and a blend of hydrogen and compressed natural gas (HCNG) that gives homogenous mixtures with high uniformity index and also to be easily connected with an Electronic Control Unit (ECU) for controlling accurately the air-gaseous fuel ratio for different engine speeds. For optimizing the homogeneity inside the new mixer, fourteen different mixer models were created to investigate the effects of diameter, location, and the number of holes inside the mixer on the homogeneity and distribution of the mixtures. Computational fluid dynamics analysis software was used to check the flow behavior, distribution and homogeneity of mixtures inside the new mixer models. The simulation results revealed that the best uniformity index (UI) values are obtained in model 7 where the UI values are 0.939 and 0.937, respectively, for an air fuel ratio for a blend of hydrogen and compressed natural gas (AFRHCNG) = 51.31 and the air fuel ratio for compressed natural gas (AFRCNG) = 34.15. According to the numerical and experimental results for the new mixer (model 7) under different engine speeds (1000–4000) and air-CNG ratio of 34.15, a meaningful agreement is reached between the experimental and numerical values for AFRCNG (coefficient of determination (R2) = 0.96 and coefficient of variation (CoV) = 0.001494).https://www.mdpi.com/1996-1073/10/9/1373homogeneity of the mixtureair-CNG-hydrogen mixerinternal combustion enginescomputational fluid dynamics (CFD)
spellingShingle Hussein A. Mahmood
Nor Mariah. Adam
B. B. Sahari
S. U. Masuri
New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
Energies
homogeneity of the mixture
air-CNG-hydrogen mixer
internal combustion engines
computational fluid dynamics (CFD)
title New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
title_full New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
title_fullStr New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
title_full_unstemmed New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
title_short New Design of a CNG-H2-AIR Mixer for Internal Combustion Engines: An Experimental and Numerical Study
title_sort new design of a cng h2 air mixer for internal combustion engines an experimental and numerical study
topic homogeneity of the mixture
air-CNG-hydrogen mixer
internal combustion engines
computational fluid dynamics (CFD)
url https://www.mdpi.com/1996-1073/10/9/1373
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AT bbsahari newdesignofacngh2airmixerforinternalcombustionenginesanexperimentalandnumericalstudy
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