A Method to Estimate the Performance Map of a Centrifugal Compressor Stage

Abstract

A novel approach to calculate the performance map of a centrifugal compressor stage is presented. At the design point four non-dimensional parameters (the flow coefficient φ, the work coefficient λ, the tip-speed Mach number M and the efficiency η) characterize the performance. In the new method the performance of the whole map is also based on these four parameters through physically-based algebraic equations which require little prior knowledge of the detailed geometry. The variable empirical coefficients in the parameterized equations can be calibrated to match the performance maps of a wide range of stage types, including turbocharger and process compressor impellers with vaned and vaneless diffusers. The examples provided show that the efficiency and the pressure ratio performance maps of turbochargers with vaneless diffusers can be predicted to within ± 2% in this way. More uncertainty is present in the prediction of the surge line, as this is very variable from stage to stage. During the preliminary design the method provides a useful reference performance map based on earlier experience for comparison with objectives at different speeds and flows.

An efficient methodology to generate optimal inputs for the preliminary design of centrifugal compressor impellers

“…As stated by many authors, 21,25 limiting M 1 rel is necessary to design high-efficiency compressors. For this end, two variants are possible: the first one is to search the geometric parameters limiting the M 1 rel by a complex optimization under constraints, which is the standard method (minimization of M 1 rel ).…”

“…For a constant flow rate and rotational speed, when the inducer tip diameter is increased the axial velocity will be reduced, but the vane speed will be important leading to a large relative velocity. Consequently, these different investigations 21,23–25 have recommended some values or ranges for the different useful design parameters.…”

Improving pre-turbine selective catalytic reduction systems in marine two-stroke diesel engines using hybrid turbocharging: A numerical study of selective catalytic reduction operation range and system fuel efficiency

“…Determining turbocharger design is simplified using a initial design method for estimating compressor and turbine performance maps with only limited design parameter inputs. For compressor map estimation, the authors have selected to use the method of previous literature works 36–38 where both optimum compressor design and resulting compressor map are estimated.…”

A zonal approach for estimating pressure ratio at compressor extreme off-design conditions

“…Together with the efficiency, the performance of the compressor is completely defined. 17 The relation between the dimensionless coefficients proposed by Jensen, defined in equation (4), is controlled with six adjustable parameters that are calibrated with a least squares method using all the available points in the measured compressor map…”