Modelling of flammable fuels in small and large scale turbulent environments

Yehia, Mohamed; Abdel-Raheem, Mohamed A.

doi:10.1016/j.fuel.2020.117110

Cited by 4 publications

(3 citation statements)

References 19 publications

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“…This discrepancy in the time needed to reach the peak pressure is a result of using the present flame surface density model. A recent parametric study by the present author [47] indicated that this discrepancy can simply be eliminated by varying the initial progress variable set to numerically ignite the mixture inside the chamber.…”

Section: Resultsmentioning

confidence: 87%

LES Analysis of Equivalence Ratio Effect on Turbulent Premixed Characteristics of LPG Flame Front Propagation

Yehia

Abdel-Aziz

Hassan

et al. 2020

The Egyptian International Journal of Engineering Sciences and

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Section: Resultsmentioning

confidence: 87%

LES Analysis of Equivalence Ratio Effect on Turbulent Premixed Characteristics of LPG Flame Front Propagation

Yehia

Abdel-Aziz

Hassan

et al. 2020

The Egyptian International Journal of Engineering Sciences and

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“…A is the model constant, the default value given by Zimont [12] is 0.52 and was later reduced to 0.38 following Yehia & Abdel-Raheem [13] , 𝑢′ is the root mean square velocity, S is the laminar flame speed, l t is turbulence length scale, τ l /𝑢′ is the turbulent time scale and τ α/ S is the chemical time scale.…”

Section: Combustion Modellingmentioning

confidence: 99%

A Numerical Study of Decarbonizing Marine Gas Turbine Emissions Through Ammonia/Hydrogen Fuel Blends

Medhat

Khalil

Yehia

2022

J. Phys.: Conf. Ser.

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The employment of gas turbine in combination with diesel engines and steam generators is a well-known power generation technique in modern marines and ship propulsion. Previously, it rendered its foundations in marine industry through higher power weight ratios and lower NOx emissions if compared to pure diesel engine driven marines. As climate change concerns are becoming more serious, the decarbonization of marine combustion products is becoming of environmental concern. In the present study a modified design of the burner and combustor was suggested to allow for the longer residence time required for releasing the combustion products from the ‘slow’ burning ammonia molecule. Afterwards, the more formidable challenge of relatively higher NOx emissions was treated through analysis of the effect of altering the equivalence ratio, hydrogen blending, increasing the combustor working pressure and staging the combustion. The latest tactic resulted in lowering values of exit NOx to around 30 ppmv, which is a quite promising result.

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“…A is the model constant, the default value given by Zimont [41] is 0.52 and was later reduced to 0.38 following Yehia & Abdel-Raheem [42], 𝑢′ is the root mean square velocity, S 𝑙 is the laminar flame speed, lt is turbulence length scale, τ 𝑡 = l 𝑡 /𝑢′ is the turbulent time scale and τ 𝑐 = α/ S 𝑙 2 is the chemical time scale.…”

Section: Combustion Modelingmentioning

confidence: 99%

A Numerical Prediction of Stabilized Turbulent Partially Premixed Flames Using Ammonia/Hydrogen Mixture

Medhat

Yehia

Khalil

et al. 2021

ARFMTS

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The objective of this work is to computationally assess the performance of a carbon free ammonia-hydrogen mixture when burnt in a gas turbine like combustor. Recently, utilizing ammonia as an alternative carbon-free fuel for future power, industry applications and achieving clean energy attracted enormous interest. Pure ammonia oxidation is facing many challenges such as high NOx emissions, high ignition energy, slow reactivity and lower laminar flame speeds. Therefore, the use of ammonia/hydrogen mixture provides flame stability and increasing flame speed. In this manuscript a numerical study for a new swirl stabilized combustor for oxidizing ammonia/hydrogen mixture. Numerical two dimensional model simulations of a turbulent flame on Reynolds Averaged Navier Stokes (RANS) including a realizable k-e turbulent scheme with the aid of chemistry mechanism were performed under various conditions. Partially premixed combustion model with flame-let concept was selected and radiation effects are also considered. Validation for the predicted results showed a reasonable agreement when validated with the experimental data. The results discuss the influence of changing inlet pressure and equivalence ratio on the stability and the characteristics of unburnt NH3 and NO emissions. Results show that for constant operating conditions such as constant equivalence ratio of 0.8 that increasing hydrogen content resulted in increasing NO emission. Also, for constant ammonia/hydrogen concentrations, NO emissions increases with equivalence ratio then reduced at rich conditions and NH3 emissions are generally low. Equivalence ratio lower than 1.2 will be preferable to reduce the amount of unburnt NH3 formation.

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Modelling of flammable fuels in small and large scale turbulent environments

Cited by 4 publications

References 19 publications

LES Analysis of Equivalence Ratio Effect on Turbulent Premixed Characteristics of LPG Flame Front Propagation

LES Analysis of Equivalence Ratio Effect on Turbulent Premixed Characteristics of LPG Flame Front Propagation

A Numerical Study of Decarbonizing Marine Gas Turbine Emissions Through Ammonia/Hydrogen Fuel Blends

A Numerical Prediction of Stabilized Turbulent Partially Premixed Flames Using Ammonia/Hydrogen Mixture

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