Towards multiobjective Nelder-Mead optimization of a HSDI diesel engine: Application of Latin hypercube design-explorer with SVM modeling approach. (1st July 2017)

• Record Type: Journal Article
• Authors: Taghavifar, Hadi
• Is Part Of: Energy conversion and management. Volume 143(2017)
• Page Start: 150
• Page End: 161
• Publication Date: 2017-07-01
• Subjects: Combustion noise -- Diesel engine -- Nelder-Mead algorithm -- Design of experiment -- SVR; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2017.04.008
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Nelder-Mead optimization and SVR modeling is conducted on a HSDI diesel engine. RunID 27 is determined as optimum case among 30 run candidates. Higher amounts of torque and swirl with lower value of combustion noise is obtained for RUNID27 than baseline. The potent modeling with statistical index of RMSE = 0.02893 is created for objective prediction. A bigger bowl and bowl center depth with small bowl middle diameter for optimum case is recommended. Abstract: Optimization process of energy-related devices is gaining an undivided attention of industrial sectors due to cost effectiveness and practicality attributes. Diesel engines are the most efficient in producing power, although there is a great capacity that has not been fully exploited. Therefore the simplex-based optimization is addressed to enhance the indicated torque (IT), combustion noise (CN), and swirl ratio (SR) of the engine at the same time. The optimum solution is reached at RunID 27, which demonstrates 7.7% increase in IT, 0.19% decrease in CN, and 21.98% increase in SR compared to those of baseline mode. In the present study, IT and CN vary inversely, thus the modification in injection schemes and chamber geometry have to be considered without putting a penalty on another. It was indicated that Min. swirl and torque cases have significantly reduced bowl volume, however, the case with the lowest swirl has lower centerline depth. In addition, it is determined that Max. torque and swirl are obtainable with a big bowl segment, although it was observed that a shallow combustion chamber is expected to induce higher torque. The higher torque is associated with more uniformity of mixture (0.8484) and pressure peak (13.98 MPa) that is plausible with a fitted spray injection with chamber walls coordination, reducing the spray-wall impingement.