A review of computational studies on the effect of physical variables in direct injection diesel engines

ABSTRACT

Diesel engines are commonly employed for transportation and power generation. Injection of diesel into the cylinder plays a crucial role towards cycle efficiency and emission regulations. The literature overview of several parameters, such as swirl ratio, injection timing, exhaust gas recirculation, fuel temperature and combustion chamber geometry, is presented in this review work. It is suggested that Computational Fluid Dynamics (CFD) simulations inside the cylinder are useful for predicting the flow field, combustion and pollutant formation. Future directions are indicated for further research on direct injection diesel engines.

KEYWORDS:

• Diesel engine
• direct injection
• parametric studies
• homogeneous charge compression ignition
• computational fluid dynamics

Acknowledgments

Author gratefully acknowledges the research grant (ECR/2018/000133) received from Science and Engineering Research Board (SERB), DST, India in carrying out this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Nomenclature

3-Z 3 zones

bTDC before Top Dead Centre

BDC Bottom Dead Centre

C Celsius

CA Crank Angle

CAD Computer-Aided Design

CFD Computational Fluid Dynamics

CO Carbon monoxide

DI Direct injection

deg degrees

ECFM extended coherent flame model

EGR Exhaust Gas Recirculation

HC Hydrocarbons

HCCI Homogeneous charge compression ignition

IT Injection timing

J Joule

NOx Oxides of nitrogen

Oh Ohnesorge number

P Pressure (bar)

PM particulate matter

Re Reynolds number

SR Swirl ratio

SMD (D₃₂) Sauter Mean Diameter

T Temperature (K)

TDC Top Dead Centre

We Weber number

Greek symbols

ε turbulent eddy dissipation rate [m²/s³]

γ ratio of specific heats

λ equivalence ratio

μ dynamic viscosity

ρ density

σ surface tension

θ crank angle

Data Availability Statement

The work presented in this review study relates to the collection of articles in the relevant field for the past 20 years or before. DOI of the referred articles is presented and hence there is no specific data available to be shared due to the nature as a review article.

Additional information

Funding

This work was supported by the Science and Engineering Research Board [ECR/2018/000133].

Notes on contributors

R. Manimaran

Manimaran Renganathanis presently working as an Associate Professor in the Thermal & Automotive Research Group, School of Mechanical Engineering at VIT Chennai campus. He has received his Ph.D in the area of investigation of reacting and non-reacting flows in CI engine with an extension to HCCI concept. He has research interests in the experimental investigation of performance and emission in a CI engine powered by hydrogen and diesel controlled by ECU. Other interests include the renewable wave energy extraction from ocean waves, machine learning algorithms applied to swirling flows during suction stroke in CI engine and general computational fluid dynamic analyses involving the temperature separation in vortex tube. Much of his work can be witnessed at manimaranweb.wordpress.com (personal webpage).