Numerical Simulation to Assess Implementation of Variable Valve Timing and Lift Technique on a BSVI LMD Diesel Engine for FE Improvement 2021-26-0421
In order to stand apart from the competition, there is an ever growing demand in Indian commercial vehicle segments to reach higher fuel economy while achieving the emission goals set by the BS-VI norms. With emissions standard set by BS-VI, novel techniques to improve fuel efficiency have to be considered that have least impact with respect to NOx and soot emissions. The optimization of exhaust and intake valve lifts with respect to engine speed, technology commonly known as Variable Valve Lift and Timing (VVT/VVL), has been implemented in many passenger vehicles propelled by gasoline engine. The aim of this work is do initial assessment of utilizing the VVL method on a LMD commercial vehicle diesel engine.
A 3.8 litre BS-VI turbocharged EGR engine is used for this study. Valve lift and timing optimization for better fuel efficiency at rated power engine speed is carried out by using one-dimensional thermodynamic simulation software AVL BOOST. For this purpose, complete engine from intake to exhaust is modelled in the simulation software and base performance calibrated with the engine test bed data. Early Intake Valve Closing (EIVC) showed BSFC improvement for rated power engine speed at full and part load conditions.
The EIVC valve lift optimized at this stage is further subjected to structural optimization with respect to valve-train dynamic and kinematic characteristics using AVL Excite. Based on the optimized EIVC valve lift characteristics a new cam profile is prepared using ISAC method and the same is carried forward for proto development to carry out POC on engine test dynamometer. The results from test bed showed improvement in BSFC which was in-line with prediction of the simulation model.
Citation: Kaundabalaraman, K., Bisht, J., and Rathi, H., "Numerical Simulation to Assess Implementation of Variable Valve Timing and Lift Technique on a BSVI LMD Diesel Engine for FE Improvement," SAE Technical Paper 2021-26-0421, 2021, https://doi.org/10.4271/2021-26-0421. Download Citation
