Showing papers by "RV Ravikrishna published in 2010"

A methodology for analysis of diesel engine in-cylinder flow and combustion

Abstract: A methodology is developed for the analysis of diesel engine in-cylinder processes and combustion. Beginning from CAD data of the engine geometry, the methodology involves use of a commercial code AVL FIRE for simulation of suction stroke, and an open-source code KIVA-3V for simulation of the closed-valve part of the diesel cycle. For this, an algorithm is first developed to map a generalised three-dimensional Computational Fluid Dynamics (CFD) solution from an unstructured mesh in AVL FIRE to a structured mesh in KIVA-3V to provide initial conditions for the closed-valve simulations. For simulation of diesel combustion process, an integrated KIVA-3V code is developed by incorporating two well-validated models into the standard code: the Shell hydrocarbon auto-ignition model for simulation of diesel auto-ignition under conditions of high temperature and pressure, and the Characteristic-time model for simulation of subsequent diesel combustion. The integrated code is validated and calibrated against experimental pressure measurements in a naturally aspirated direct injection diesel engine. These tools are then used for exploring the potential of a constant-speed, turbocharged diesel engine towards emission reduction. The case study involves combustion simulations for exploring multiple injection strategy for the engine concerned.

Potential of bio-DME as a transportation fuel for India

Abstract: This article discusses the potential of bio-dimethyl ether (DME) as a promising fuel for India in the transportation sector where a majority of imported petroleum in the form of diesel is used. Specifically, the suitability of DME in terms of its properties vis-a-vis those of diesel, ability to liquefy DME at low pressures similar to liquefied petroleum gas (LPG), and ease of production from renewable feedstock (biomass), and most importantly, very low emissions including near-zero soot levels are some of the features that make it an attractive option. A detailed review presents the state-of-the-art on various aspects such as estimates of potential bio-DME production, methods of synthesis of bio-DME, important physicochemical properties, fuel-injection system-related concerns (both conventional and common-rail system), fuel spray characteristics which have a direct bearing on the engine performance, and finally, exhaust emissions. Future research directions covering all aspects from production to utilization are summarized (C) 2010 American Institute of Physics. doi:10.1063/1.3489529]