NUI Galway College of Engineering and Informatics


Sajjad Yousefian

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Summary and objectives

Society faces serious challenges in the form of climate change, energy supply security and the cost of energy. The world currently relies on fossil fuels for over 80% of its energy needs. There is a clear need to research and develop new sustainable and ideally renewable forms of energy. A particularly difficult challenge is the replacement of fossil-based fuels for road and air transportation. This is due the very high energy density of the incumbent fuels. Research into sustainable next generation biofuels is therefore essential. The Combustion Chemistry Centre (C3) at NUI Galway studies the combustion performance of new fuels using experimental devices known as Rapid Compression Machines (RCMs).

RCMs are widely used to study autoignition chemistry, a key fuel characteristic, at low to intermediate temperatures, similar to conditions in advanced combustion systems, such as internal combustion engines and lean premixed burners of gas turbines. Experimental data of ignition delays from RCMs is used to develop and validate chemical kinetic mechanisms, which are used to model engine and fuel performance. While RCMs represent idealisations of engine conditions, aerodynamic phenomena can still affect the accuracy of measurements. This work seeks to characterise and mitigate these phenomena.

There are different methods to characterize fluid dynamics in RCMs, such as computational fluid dynamics (CFD) and experimental measurements for temperature distribution using techniques such as laser-induced florescence (LIF) and OH chemiluminescence. Systematic numerical approaches, such as genetic algorithms, integrated with CFD can also be used to optimize machine design and therefore performance. The objective of this research is to use these numerical and experimental methods to characterize current RCM performance and optimize its design for better determination of ignition delay time.

Projected research outputs

-  Characterization of temperature and velocity flow field in RCM with using numerical and experimental approaches.

-  Sensitivity analysis of thermos-physical and geometrical parameters for temperature inhomogeneity in RCM.

-  Development of correlation to predict temperature inhomogeneity in RCM.

-  Development of optimized geometry for RCM to minimise temperature inhomogeneity.

Conferences proceedings

Yousefian S, Curran HJ, Banyon C, Gauthier F, Moran-Guerrero A, Richardson RR, Quinlan NJ, Monaghan RFD. Numerical Characterization and Sensitivity Analysis of Post-Compression Temperature Non-Uniformity in a Twin-Piston Rapid Compression Machine. European Combustion Meeting,Budapest, Hungary, Mar 2015

S Yousefian, NJ Qinlan, HJ Curran, RFD Monaghan. Large eddy simulation of turbulent flow field development in a rapid piston machine. 11th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements, Palermo, Italy, September 21-23, 2016

S Yousefian, T Marzullo, G Bourque, RFD Monaghan. Study of systematic flow field discretization methods for hybrid CFD-CRN emissions modelling. 8th European Combustion Meeting, Dubrovnik, Croatia, April 18-21, 2017

 S Yousefian, G Bourque, RFD Monaghan. Comparison of Hybrid Emissions Prediction tools and Uncertainty Quantification Methods for Gas turbine combustion systems. Turbomachinery Technical Conference & Exhibition ASME Turbo Expo 2017, Charlotte, USA, June 26-30, 2017

Journal publications

A simplified approach to the prediction and analysis of temperature inhomogeneity in rapid compression machines. S Yousefian, F Gauthier, A Morán-Guerrero, RR Richardson, HJ Curran, NJ Quinlan, RFD Monaghan. 2015. Energy & Fuels 29 (12), 8216 - 8225



Rapic Compression Machine Facility - C3 Research Group - NUI Galway