Off-Design Computer Code for Calculating the Aerodynamic Performance of Axial-Flow Fans and Compressors


Book Description

An off-design axial-flow compressor code is presented and is available from COSMIC for predicting the aerodynamic performance maps of fans and compressors. Steady axisymmetric flow is assumed and the aerodynamic solution reduces to solving the two-dimensional flow field in the meridional plane. A streamline curvature method is used for calculating this flow-field outside the blade rows. This code allows for bleed flows and the first five stators can be reset for each rotational speed, capabilities which are necessary for large multistage compressors. The accuracy of the off-design performance predictions depend upon the validity of the flow loss and deviation correlation models. These empirical correlations for the flow loss and deviation are used to model the real flow effects and the off-design code will compute through small reverse flow regions. The input to this off-design code is fully described and a user's example case for a two-stage fan is included with complete input and output data sets. Also, a comparison of the off-design code predictions with experimental data is included which generally shows good agreement. Schmidt, James F. Unspecified Center...




Analysis of the Effects of Design Pressure Ratio Per Stage and Off-design Efficiency on the Operating Range of Multistage Axial-flow Compressors


Book Description

Multistage compressors composed of high-pressure-ratio stages have higher over-all off-design efficiencies and a wider operating range than those made up of low-pressure-ratio stages if the blade-row efficiency curves for the two cases are assumed to be somewhat similar.




NASA Technical Note


Book Description




Non-uniform Radial Meanline Method for Off-design Performance Estimation of Multistage Axial Compressors


Book Description

The increasing use of renewable energy sources necessitates power-generating gas turbines capable of frequently and rapidly starting up to supplement the energy supply when renewable sources alone cannot meet demand [1], [21. This makes the off-design performance of such gas turbines more important as they spend more of their operational life off the design point. Currently off-design performance cannot be estimated with high fidelity until late in the gas turbine compressor design process at which point the design is largely fixed and only limited changes can be made. This thesis presents a Non-Uniform Radial Meanline method for multistage axial compressor off-design performance estimation, capturing the transfer of radial flow non-uniformity and its impact on compressor blade row performance. This method enables the high-fidelity characterization of blade row performance and the stage matching of multistage compressors with non-uniformity effects included. A new representation of non-uniform radial flow profiles using orthonormal basis functions was developed to provide a compact representation suitable for inclusion in a one-dimensional performance estimation method. The link between radial flow non-uniformity and compressor blade row performance was characterized using three-dimensional embedded stage calculations. An initial implementation of the Non-Uniform Radial Meanline method was demonstrated for different compressor inlet non-uniformities. The computations show that the new approach provides an effective means of incorporating radial flow non-uniformity into a one-dimensional compressor performance estimation method.




Axial Flow Compressors


Book Description




Axial Flow Fans and Compressors


Book Description

Provides readers with an understanding of aerodynamic design and performance of fans and compressors. The book includes practical emphasis on design problems, experimental facilities and data analysis, together with some design examples and novel concepts.