Two-stage system identification approach for three-dimensional structural systems

The modern internal combustion engine (ICE) has to meet several requirements. It has to be reliable with the reduced emission of pollutant gasses and low maintenance requirements. What is more, it has to be efficient both at low-load and high-load operating conditions. For this purpose, a variable turbine geometry (VTG) turbocharger is used to provide proper engine acceleration of exhaust gases at low-load operating conditions. Such a solution is also efficient at high-load engine operating conditions. In this paper, the result of an unsteady, three-dimensional (3D) simulation of the variable two-stage turbine system is discussed. Three different VTG positions were considered for those simulations, along with three different turbine speeds. The turbine inlet was modeled as six equally placed exhaust pipes for each cylinder to eliminate the interference of pressure waves. The flow field at the outlet of the 1st stage nozzle vane and 2nd stage rotor was investigated. The simulations showed that the variable technologies significantly improve the efficiency of the two-stage turbine system. The highest overall efficiency of the two-stage system was achieved at 60,000 rpm and 11o VTG position.

Download Full-text

Experimental analysis of vehicle–bridge interaction using a wireless monitoring system and a two-stage system identification technique

Mechanical Systems and Signal Processing ◽

10.1016/j.ymssp.2011.12.008 ◽

2012 ◽

Vol 28 ◽

pp. 3-19 ◽

Cited By ~ 53

Author(s):

Junhee Kim ◽

Jerome P. Lynch

Keyword(s):

System Identification ◽

Monitoring System ◽

Experimental Analysis ◽

Two Stage ◽

Wireless Monitoring ◽

Identification Technique ◽

Stage System

Download Full-text

Two-Stage System Identification Method Incorporating with Pre-Identification Result

Transactions of the Institute of Systems Control and Information Engineers ◽

10.5687/iscie.29.101 ◽

2016 ◽

Vol 29 (2) ◽

pp. 101-103

Author(s):

Ayaka Matsubayashi ◽

Masaki Inoue ◽

Shuichi Adachi

Keyword(s):

System Identification ◽

Two Stage ◽

System Identification Method ◽

Identification Method ◽

Stage System

Download Full-text

The anaerobic treatment of a ligno-cellulosic substrate offering little natural pH buffering capacity

Water Science & Technology ◽

10.2166/wst.1998.0574 ◽

1998 ◽

Vol 38 (4-5) ◽

pp. 29-35 ◽

Cited By ~ 17

Author(s):

C. J. Banks ◽

P. N. Humphreys

Keyword(s):

Ph Control ◽

Anaerobic Treatment ◽

Buffering Capacity ◽

Single Stage ◽

Stable Operation ◽

Reactor Performance ◽

Two Stage ◽

Ph Buffering ◽

Stage System ◽

The Stability

The stability and operational performance of single stage digestion with and without liquor recycle and two stage digestion were assessed using a mixture of paper and wood as the digestion substrate. Attempts to maintain stable digestion in both single stage reactors were unsuccessful due to the inherently low natural buffering capacity exhibited; this resulted in a rapid souring of the reactor due to unbuffered volatile fatty acid (VFA) accumulation. The use of lime to control pH was unsatisfactory due to interference with the carbonate/bicarbonate equilibrium resulting in wide oscillations in the control parameter. The two stage system overcame the pH stability problems allowing stable operation for a period of 200 days without any requirement for pH control; this was attributed to the rapid flushing of VFA from the first stage reactor into the second stage, where efficient conversion to methane was established. Reactor performance was judged to be satisfactory with the breakdown of 53% of influent volatile solids. It was concluded that the reactor configuration of the two stage system offers the potential for the treatment of cellulosic wastes with a sub-optimal carbon to nitrogen ratio for conventional digestion.

Download Full-text