Design and testing a bespoke cylinder head pulsating flow generator for a turbocharger gas stand

Vijayakumar, Ramkumar; Akehurst, Sam; Liu, Zhongjian; Reyes-Belmonte, Miguel A.; Brace, Chris; Liu, D.; Copeland, Colin

doi:10.1016/j.energy.2019.116291

Cited by 9 publications

(6 citation statements)

References 34 publications

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“…Even though the synergy of turbocharging and CDA can be beneficial, CDA can affect the compressor surge line. For example, in the three-cylinder engine, one deactivated cylinder resulted in moving the surge line by 29-54% to the right and in experiencing greater sensitivity to the frequency of pulsations [73]. Another consequence of CDA is an increase in the temperature of the components.…”

Section: Negative Effectsmentioning

confidence: 99%

Overview of the potential and limitations of cylinder deactivation

Fridrichová

Drápal

Vopařil

et al. 2021

Renewable and Sustainable Energy Reviews

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Section: Negative Effectsmentioning

confidence: 99%

Overview of the potential and limitations of cylinder deactivation

Fridrichová

Drápal

Vopařil

et al. 2021

Renewable and Sustainable Energy Reviews

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“…Speed fluctuations caused by the pulsated flow of exhaust gases in the turbine reduce the efficiency of the compressor and the turbine. [14][15][16] The cumulative effects of high-speed and axial thrust fluctuations and high thermal loads lead to deterioration of the rotating parts and reduce the turbocharger's life. 12,13 During the blowdown period, the turbine offers some resistance to the exhaust gas flow, which creates a back pressure in the exhaust port.…”

Section: Introductionmentioning

confidence: 99%

“…[7][8][9][10] A plenum volume of around five to six times the engine displacement was required to increase the power output. However, the pulsated flow of exhaust gases in the turbine would still cause the speed of the turbocharger to fluctuate, 14,15 reducing the compressor and the turbine efficiencies. 16 A method of utilizing two separate exhaust lines from a single-cylinder engine to deliver the exhaust gases to the turbocharger turbine was suggested.…”

Section: Introductionmentioning

confidence: 99%

A novel method to overcome the shortcomings of turbocharging a single cylinder diesel engine

Ramkumar

Krishnasamy

Ramesh

2021

International Journal of Engine Research

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Single-cylinder diesel engines are generally not turbocharged because of highly pulsating exhaust gas flow, resulting in increased speed fluctuations and reduced turbine performance. In the present work, a novel and simple method is proposed wherein an exhaust plenum is placed before the turbine to reduce the flow fluctuations. A production light-duty naturally aspirated (NA) diesel engine modified into the turbocharged version was incorporated with an exhaust plenum. Steady-state experiments were performed with the base naturally aspirated engine, the turbocharged version without an exhaust plenum (conventional pulse turbocharging), and the turbocharged version with the exhaust plenum. The present work attempts to establish the limitations of conventional pulse turbocharging in a single-cylinder diesel engine unavailable in the existing literature. Though the conventional pulse turbocharged version could deliver a boost pressure of about 2 bar (absolute), a brake power reduction of 40% and the associated drop in brake mean effective pressure was observed compared to the base NA engine due to high exhaust back pressures. The pumping work was four times higher in conventional pulse turbocharging than the NA engine, thus reducing the performance. After validating the simulation models, a one-dimensional simulation tool was used to evaluate the effect of incorporating exhaust plenum before the turbine. Simulated results predicted the brake power output within a 3% error for the NA and plenum turbocharging configurations. An optimal plenum volume was arrived at using the validated simulation model. Subsequent experiments on the turbocharged engine with the plenum in place showed a significant improvement in the engine performance and reduced exhaust emissions compared to the NA version. Brake power output was enhanced by 25%, which indicated improved thermal efficiency of 2%. Compared to the NA version, the soot, carbon monoxide (CO) and unburned hydrocarbon HC emissions were reduced by 93%, 88%, and 53%, respectively. However, an increase in oxides of nitrogen (NOx) emissions was seen, which can be controlled with suitable mitigation methods taking advantage of the significantly lower soot levels. Thus, the proposed method of placing an exhaust plenum before the turbine makes turbocharging viable on single-cylinder diesel engines with performance improvement and emission reduction when suitable NOx mitigation measures are adopted.

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“…The 1D engine models can imitate the realistic pulsating flow and provide more detailed pulse events. On reflection, R. Vijayakumar et al [22] employed 1D engine modelling capability in order to design and manufacture a hot gas pulse generator to investigate the turbine performance under various pulsating flow conditions. The coupling of 1D and 3D-CFD turbine models can provide a better understanding of pulsating flow behaviour in turbocharger turbines [23,24].…”

Section: Introductionmentioning

confidence: 99%

Computational Study of a Radial Flow Turbine Operates Under Various Pulsating Flow Shapes and Amplitudes

Rezk

Sharma

Barrans

et al. 2021

Journal of Energy Resources Technology

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Radial flow turbines are extensively used in turbocharging technology due to their unique capability of handling a wide range of exhaust gas flow. The pulsating flow nature of the internal combustion engine exhaust gases causes unsteady operation of the turbine stage. This paper presents the impact of the pulsating flow of various characteristics on the performance of a radial flow turbine. A three-dimensional computational fluid dynamic model was coupled with a one-dimensional engine model to study the realistic pulsating flow. Applying square wave pulsating flow showed the highest degree of unsteadiness corresponding to 92.6% maximum mass flow accumulation due to the consecutive sudden changes of the mass flowrates over the entire pulse. Although sawtooth showed a maximum mass flow accumulation value of 88.9%, the mass flowrates entailed gradual change and resulted in the least overall mass flow accumulation over the entire pulse. These two extremes constrained the anticipated performance of the radial flow turbine that operates under realistic pulsating flow. Such constraints could develop an operating envelope to predict the performance and optimize radial flow turbines’ power extraction under pulsating flow conditions.

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Design and testing a bespoke cylinder head pulsating flow generator for a turbocharger gas stand

Cited by 9 publications

References 34 publications

Overview of the potential and limitations of cylinder deactivation

Overview of the potential and limitations of cylinder deactivation

A novel method to overcome the shortcomings of turbocharging a single cylinder diesel engine

Computational Study of a Radial Flow Turbine Operates Under Various Pulsating Flow Shapes and Amplitudes

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