The new two-stage turbocharged six-cylinder diesel engine of the BMW 740d

Practical aspects of light-duty diesel combustion system design are reviewed, with an emphasis on design considerations reported by manufacturers and engine design consultancies. The factors driving the selection of compression ratio, stroke-to-bore ratio, and various aspects of combustion chamber geometry are examined, along with the trends observed in these parameters in recently released engines. The interactions among geometric characteristics, swirl ratio, and the fuel injection nozzle parameters are also reviewed.

show abstract

“…Consequently, many new engine designs feature vertical valves and no valve pockets in the piston top. 14,[25][26][27][28][29]…”

Section: Axisymmetrymentioning

confidence: 99%

A review of design considerations for light-duty diesel combustion systems

Miles

Andersson

2015

International Journal of Engine Research

View full text Add to dashboard Cite

show abstract

“…A VGT adjustable blade regulation was added to this system, and the number of corresponding valve control manifold absolute pressure (map) was increased from 4 to 5. 16 Regarding system control, the BMW study remained based on steady-state control strategies and only partially considered transient performance in establishing a steady-state control strategy. It is difficult to reconcile the demands for better steady-state fuel economy and transient response performance.…”

Section: Introductionmentioning

confidence: 99%

Steady-state and transient control strategies for a two-stage turbocharged diesel engine

Deng

Cui

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

Two-stage turbocharging technology is widely used to achieve higher engine power density and lower exhaust emissions. To solve a series of contradictions in matching, a regulated two-stage (RTS) turbocharging system is applied to reasonably control boost pressure. This paper investigated steady-state and transient control strategies for an RTS turbocharging system to achieve optimum fuel economy in steady-state conditions and better performance in transient conditions. The economic control strategies for steady-state operational conditions were based on an economic regulation law, which was established by a steady-state test of an engine with an RTS turbocharging system under all operating conditions. To optimize the transient performance, open-loop and closed-loop control systems (the latter with dynamic judgement) for the RTS system were designed and validated with experiments on a heavy-duty diesel engine. The experimental results demonstrated that the open-loop control strategy and the closed-loop strategy with dynamic judgement could improve the transient response performance. The optimum transient response performance was achieved by the closed-loop control system with dynamic judgement. Additionally, the combination of steady-state and transient control strategies could achieve the best fuel economy in steady-state conditions and good transient response performances.

show abstract