Mayura H Halbe

Bio: Mayura H Halbe is an academic researcher from Purdue University. The author has contributed to research in topics: Diesel engine & Combustion. The author has an hindex of 2, co-authored 2 publications receiving 9 citations.

Control-oriented premixed charge compression ignition CA50 model for a diesel engine utilizing variable valve actuation

Abstract: Premixed charge compression ignition (PCCI) is a promising combustion strategy for reducing in-cylinder NOx and particulate matter formation in diesel engines without incurring fuel penalty. Howeve...

Oil Accumulation and First Fire Readiness Analysis of Cylinder Deactivation

Abstract: Cylinder deactivation (CDA) is a technology that can improve the fuel economy and exhaust thermal management of compression ignition engines (diesel and natural gas), especially at low loads and engine idling conditions. The reduction in engine displacement during CDA improves fuel efficiency at low loads primarily through a reduction in pumping work. During deactivation of a given cylinder the drop in pres- sure inside the cylinder could possibly lead to the transport of oil from the crankcase into the cylinder owing to the reduced pressure difference between the crankcase and the cylinder. In addition, cylinder deactivation might inhibit the first fire readiness of a reactivating cylinder as a result of reduced wall, head, and piston temperatures. Both of these potential issues are quantitatively studied in this paper. This paper describes a strategy to estimate in-cylinder oil accumulation during CDA, and first fire readiness following CDA, through comparison of individual heat realease profiles before and after CDA. Cylinder cool-down and oil accumulation dur- ing deactivation could possibly result in misfire or degraded combustion upon an at- tempt to reactivate a given cylinder. Fortunately, experiments described in this paper demonstrate no cases of misfire at any speed/load conditions for the CDA durations tested, specifically, 100 ft-lb load at 800 rpm and 1200 rpm with deactivation intervals of 0.5, 5, 10 and 20 minutes. Although pilot heat release in the reactivated cylinders was delayed by approximately 1 CAD after 5 minutes of CDA, the main heat release was very similar to the heat release of a continuously activated cylinder. As such, results show no first fire readiness issues at the conditions tested. The duration of time the engine could be operated in CDA mode without significant oil accumulation, and other methods to minimize oil accumulation during CDA have also been proposed.

Model Predictive Control of an Advanced Multiple Cylinder Engine With Partially Premixed Combustion Concept

Abstract: Partially premixed combustion (PPC) is an advanced combustion concept and powertrain technology, which has a great potential to improve the fuel economy of vehicles. The process of PPC is driven by both chemical kinetics and mixing process, and is, therefore, sensitive to inlet conditions and injection process. This article presents a control-oriented combustion and air-path model of a PPC multicylinder engine, and also proposes a model predictive control framework for its transient control. The control system was validated in a transient scenario and its capability was demonstrated through a large range of load transient operation.

Comparative study of diesel engine cylinder deactivation transition strategies

Abstract: Cylinder deactivation is an effective strategy to improve diesel engine fuel efficiency and aftertreatment thermal management when implemented through deactivation of both fueling and valve motion ...

Exhaust Thermal Management Using Cylinder Deactivation and Late Intake Valve Closing

Abstract: Magee, Mark E. M.S.M.E., Purdue University, May 2014. Exhaust Thermal Management using Cylinder Deactivation and Late Intake Valve Closing. Major Professor: Gregory M. Shaver, School of Mechanical Engineering. Progressively stricter emission regulations have compelled diesel engine manufacturers to develop new technologies that reduce harmful pollutants like NOx and soot. While manufacturers have previously been able to meet these regulations through the use of on engine technology such as exhaust gas recirculation and multiple pulse injections, exhaust after treatment systems such as diesel particulate filters and selective catalytic reduction systems have become necessary to meet recent stricter policies. While these after treatment systems are incredibly effective at reducing harmful emissions, to operate effectively the system needs to be above a certain temperature level typically between 250 and 300◦C. Many methods such as additional fueling or electrical heaters have been explored and used to increase the temperature of the exhaust gases passing through these systems to heat them faster or maintain temperature. The effect of cylinder deactivation, CDA, and late intake valve closing, LIVC, on raising exhaust gas temperatures was studied by performing load sweeps at 1200 RPM. The effect of CDA, CDA and LIVC, and CDA meeting specific NOx targets was analyzed. At low loads, CDA proved to be effective at raising exhaust temperature as well as providing an improvement in brake thermal efficiency, BTE. At higher loads, exhaust gas temperatures were also improved, but with a fuel consumption penalty. The introduction of LIVC in combination with CDA increased exhaust temperatures above 250◦C, but did not improve BTE. The last sweeps, which targeted low NOx emissions, required the use of EGR and were able to raise temperatures above 250◦C across all loads while meeting the targets. While meeting the targets, BTE was only improved at low loads.