scholarly journals Local Gas Holdup and Gas Recirculation Rate in an Aerated Vessel Equipped with a Rushton Turbine Impeller.

1996 ◽  
Vol 29 (5) ◽  
pp. 799-804 ◽  
Author(s):  
Katsuhide Takenaka ◽  
Koji Takahashi
Keyword(s):  
Gas Holdup ◽  
Rushton Turbine ◽  
Recirculation Rate ◽  
Gas Recirculation ◽  
Turbine Impeller

Effect of Baffle Length on Power Consumption in Turbulent Mixing Vessel with Rushton Turbine Impeller

2011 ◽  
Vol 37 (2) ◽  
pp. 147-149 ◽  
Author(s):  
Yoshihito Kato ◽  
Noboru Kamei ◽  
Yutaka Tada ◽  
Azusa Nakaoka ◽  
Yuichiro Nagatsu ◽  
...  
Keyword(s):  
Power Consumption ◽  
Turbulent Mixing ◽  
Rushton Turbine ◽  
Turbine Impeller

scholarly journals Learning reference governor for cycle-to-cycle combustion control with misfire avoidance in spark-ignition engines at high exhaust gas recirculation–diluted conditions

2020 ◽  
Vol 21 (10) ◽  
pp. 1819-1834
Author(s):  
Bryan P Maldonado ◽  
Nan Li ◽  
Ilya Kolmanovsky ◽  
Anna G Stefanopoulou
Keyword(s):  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
Operating Conditions ◽  
Intake Manifold ◽  
Exhaust Gas ◽  
Model Free ◽  
Recirculation Rate ◽  
Valve Position ◽  
Gas Recirculation ◽  
Reference Governor

Cycle-to-cycle feedback control is employed to achieve optimal combustion phasing while maintaining high levels of exhaust gas recirculation by adjusting the spark advance and the exhaust gas recirculation valve position. The control development is based on a control-oriented model that captures the effects of throttle position, exhaust gas recirculation valve position, and spark timing on the combustion phasing. Under the assumption that in-cylinder pressure information is available, an adaptive extended Kalman filter approach is used to estimate the exhaust gas recirculation rate into the intake manifold based on combustion phasing measurements. The estimation algorithm is adaptive since the cycle-to-cycle combustion variability (output covariance) is not known a priori and changes with operating conditions. A linear quadratic regulator controller is designed to maintain optimal combustion phasing while maximizing exhaust gas recirculation levels during load transients coming from throttle tip-in and tip-out commands from the driver. During throttle tip-outs, however, a combination of a high exhaust gas recirculation rate and an overly advanced spark, product of the dynamic response of the system, generates a sequence of misfire events. In this work, an explicit reference governor is used as an add-on scheme to the closed-loop system in order to avoid the violation of the misfire limit. The reference governor is enhanced with model-free learning which enables it to avoid misfires after a learning phase. Experimental results are reported which illustrate the potential of the proposed control strategy for achieving an optimal combustion process during highly diluted conditions for improving fuel efficiency.

Effect of balance valve on an asymmetric twin-scroll turbine for heavy-duty diesel engine

2020 ◽  
pp. 146808742093016
Author(s):  
Jianjiao Jin ◽  
Jianfeng Pan ◽  
Zhigang Lu ◽  
Qingrui Wu ◽  
Lizhong Xu
Keyword(s):  
Fuel Economy ◽  
High Speed ◽  
Engine Speed ◽  
Flow Parameter ◽  
Engine Performance ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Fuel ◽  
Recirculation Rate ◽  
Gas Recirculation

A conventional asymmetric twin-scroll turbine with wastegate is capable of effectively tackling down the contradiction between fuel economy degradation and low nitrogen oxide emissions. However, as the engine speed has been rising at middle- and high-speed ranges, the pressure of small scroll inlet will be increasingly higher as compared with the intake pressure, thereby worsening fuel economy. In this study, a novel turbocharging technology of asymmetric twin-scroll turbine with a balance valve was first analyzed to more effectively balance the engine fuel economy and emission. The experiments on turbine test rig and engine performance were performed to explore the effects of balance valve on turbine performance, asymmetric ratio, exhaust gas recirculation rate, as well as engine performance. As the balance valve open degree was elevated, the turbine flow parameter was being extended, while the turbine efficiency was enhanced. Moreover, a lower asymmetric ratio could lead to a broader flow parameter range between that of partial admission and equal admission, thereby resulting in a broader regulating range of exhaust gas recirculation rate. In contrast with the asymmetric twin-scroll turbine with wastegate, the turbine running efficiency of asymmetric twin-scroll turbine with balance valve was enhanced by nearly 2%–11% at middle and high engine speed ranges, while the fuel economy was improved by nearly 1.5%–8%.

scholarly journals Power Input of High-Speed Rotary Impellers

10.14311/280 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
K. R. Beshay ◽  
J. Kratěna ◽  
I. Fořt ◽  
O. Brůha
Keyword(s):  
Pitch Angle ◽  
High Speed ◽  
Power Input ◽  
Cylindrical Vessel ◽  
Turbulent Regime ◽  
Power Dependence ◽  
Rushton Turbine ◽  
Weak Influence ◽  
Turbine Impeller ◽  
Blade Pitch Angle

This paper presents the results of an experimental investigation of the power input of pitched blade impellers and standard Rushton turbine impellers in a cylindrical vessel provided with four radial baffles at its wall under a turbulent regime of flow of an agitated liquid. The influence of the geometry of the pitched blade impellers (pitch angle, number of blades) and the off-bottom impeller clearance of both high-speed impellers tested on the impeller power input is determined in two sizes of the cylindrical vessel (0.3 m and 0.8 m diameter of vessel). A strain gauge torquemeter is used in the small vessel and a phase shift mechanical torquemeter is used in the large vessel. All results of the experiments correspond to the condition that the Reynolds number modified for the impeller exceeds ten thousand. The results of this study show that the significant influence of the separating disk thickness of the turbine impeller corresponds fairly well to the empirical equations presented in the literature. Both the influence of the number of impeller blades and the blade pitch angle of the pitched blade impeller were expressed quantitatively by means of the power dependence of the recently published correlations: the higher the pitch angle and the number of blades, the higher the values of the impeller power input. Finally, it follows from results of this study that the impeller off-bottom clearance has a weak influence on the power input of the Rushton turbine impeller, but with decreasing impeller off-bottom clearance the power input of the pitched blade impeller increases significantly.

Model Based Boost Pressure and Exhaust Gas Recirculation Rate Control for a Diesel Engine With Variable Turbine Geometry

2001 ◽  
Vol 34 (1) ◽  
pp. 277-282 ◽  
Author(s):  
Joachim Rückert ◽  
Axel Schloßer ◽  
Heinrich Rake ◽  
Bert Kinoo ◽  
Michael Krüger ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Rate Control ◽  
Exhaust Gas Recirculation ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Variable Turbine Geometry ◽  
Model Based ◽  
Recirculation Rate ◽  
Gas Recirculation

scholarly journals Structure of turbulent velocity field in the discharge stream from a standard Rushton turbine impeller

2017 ◽  
Vol 23 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Bohus Kysela ◽  
Jiří Konfrst ◽  
Zdeněk Chára ◽  
Ivan Fořt
Keyword(s):  
Radial Direction ◽  
Laser Doppler Anemometry ◽  
Periodic Part ◽  
Spatial Distributions ◽  
Measurement Point ◽  
Rushton Turbine ◽  
Axial Profile ◽  
Similar Range ◽  
Turbulent Velocity Field ◽  
Turbine Impeller

The radial discharge jet from a standard Rushton turbine was investigated by the Laser Doppler Anemometry (LDA) method. Several distances from the impeller blades (in the radial direction) were chosen for the measurement of axial profiles: all three velocity components (radial, tangential and axial) were measured at each point of the axial profile. The obtained velocity time records were analysed and averaged results were decomposed into three parts: mean ensembleaverage, random and periodic. The ratio of the derived periodic part of the velocity was evaluated in each measurement point and for all velocity components. The obtained results indicate the regions where the periodic part of the velocity has significant effect and where the contribution of this part is almost negligible. Although the values of the periodic part of all velocity components have a rather similar range, the spatial distributions are different in the investigated region.

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