Research Publications

Abam D P S


Dr. D.P.S. Abam and E.G. Saturday.

Corresponding Author:

 Dr. D.P.S. Abam.

Department of Mechanical Engineering, Faculty of Engineering,

University of Port Harcourt, Port Harcourt,


TITLE: Optimization of Centrifugal Compressors: A Case Study




This paper presents the optimization of centrifugal compressors. The purpose is to obtain optimal flow conditions in centrifugal compressors. The analysis is with respect to the effect of the degree of pre-whirl on the optimal inlet relative flow angle and hence the optimal mass flow rate achievable at various in let relative Mach numbers for different values of the compressor inducer geometric parameter. A mass flow function incorporating al l these parameters was developed and analyzed in a MATLAB environment to obtain the optimal inlet relative flow angle and the corresponding optimal mass flow rate at a given rotational speed of the compressor. The optimal inlet relative flow angle increases with the inlet relative Mach number at the given degree of pre-whirl, but decreases with an increase in the degree of pre-whirl at the given inlet relative Mach number. Also the optimal mass flow rates for computed values of the geometric parameter fall between those for two extreme allowable values of this parameter. The optimal rotational speed at a defined mass flow rate could be obtained from the analysis, and the results of this work will serve as guide for both design and operation of centrifugal compressors.


Key words:

Centrifugal compressors, optimization, optimal mass flow rates, degree of pre-whirl, MATLAB



ISSN: 2141-7016




 Dr. D.  P. S Abam, BSc, PhD, AMIMechE1.

Department of Mechanical Engineering, University of Port Harcourt, Port Harcourt, Federal Republic of Nigeria.

TITLE: Methane Combustion in Laminar Diffusion Flames



This paper is concerned with methane combustion in laminar diffusion flames. Data on methane concentration distributions in different diffusion flame geometries are correlated against a conserved scalar called mixture fraction. The correlation is used to determine a global methane combustion rate applicable in the rich to stoichiometric regions of laminar diffusion flames. The global rate is consistent with methane disappearance through the forward kinetic step:

CH4 + H → CH3 + H2

with [H] equilibrated according to


on the rich side. This equilibration results from the three-body reaction


which is equilibrated in the region 1.1 ≤ φ ≤ 2.74, 1300 K ≤ T ≤ 2000 K.

These results indicate that initial radical attack on the fuel molecule provides the rate-controlling step for methane combustion.

  • Received September 10, 1987.
  • Accepted August 9, 1988. 
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