Innovations in Body Force Modeling of Transonic Compressor Blade Rows

• Published in: International journal of rotating machinery Vol. 2018; no. 2018; pp. 1 - 12
• Main Authors: Hill, David J., Defoe, Jeffrey J.
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2018; Hindawi; John Wiley & Sons, Inc; Wiley
• Subjects: Aerodynamics; Compressor blades; Distortion; Efficiency; Flow coefficients; Mathematical models; Noise; Predictions; Propagation; Transonic compressors; Transonic flow; Turbulence models; Uniform flow; Velocity
• ISSN: 1023-621X; 1542-3034
• DOI: 10.1155/2018/6398501

Aeroengine fans and compressors increasingly operate subject to inlet distortion in the transonic flow regime. In this paper, innovations to low-order numerical modeling of fans and compressors via volumetric source terms (body forces) are presented. The approach builds upon past work to accommodate any axial fan/compressor geometry and ensures accurate work input and efficiency prediction across a range of flow coefficients. In particular, the efficiency drop-off near choke is captured. The model for a particular blade row is calibrated using data from single-passage bladed computations. Compared to full-wheel unsteady computations which include the fan/compressor blades, the source term model approach can reduce computational cost by at least two orders of magnitude through a combination of reducing grid resolution and, critically, eliminating the need for a time-resolved approach. The approach is applied to NASA stage 67. For uniform flow, at 90% corrected speed and peak-efficiency, the body force model is able to predict the total-to-total pressure rise coefficient of the stage to within 1.43% and the isentropic efficiency to within 0.03%. With a 120 ∘ sector of reduced inlet total pressure, distortion transfer through the machine is well-captured and the associated efficiency penalty predicted with less than 2.7% error.