SAE ARP 1420C:2017 pdf free

SAE ARP 1420C:2017 pdf free.Gas Turbine Engine Inlet Flow Distortion Guidelines
The AIP pressure-probe data are used to describe inlet distortion directly in terms of the probe readings (pattern) and numerically in terms of a distortion descriptor that is related to the severity of the distortion. The distortion descriptor provides a means of identifying critical inlet flow distortions and of communicating during propulsion system development. A universal distortion descriptor is beyond the state of the art; however, distortion-descriptor elements have been identified for use in structuring a distortion descriptor for a particular engine. These elements should be used to define each distortion descriptor system and its associated computation procedure.
Distortion-Descriptor Elements:The distortion-descriptor elements are used to describe the distortion at the AIP. The fundamental element is the set of pressure-probe readings that are used to describe the pressure distribution at the AIP. The pressure probes are usually arranged in rake and probe arrays, as described in Section 8 (see Figure 2). Circumferential and radial distortion elements (obtained using the pressure-probe readings) are described on a ring-by-ring basis, as described below and in detail in the Appendix.
By a combination of the distortion-descriptor elements described above and the stability and performance assessment techniques described in Section 6, the developer will define a set of inlet distortion descriptors for use in describing inlet distortion levels at the AIP. These descriptors may be used for inlet distortion screening to evaluate inlet/engine compatibility prior to any inlet/engine testing. Inlet distortion screening is accomplished by converting the probe readings at the AIP into numerical distortion descriptors, which are then compared to allowable levels of distortion based on a stability and performance assessment of a specific engine model.
Quantitative evaluations of compressor stability and engine performance may be necessary to provide technical visibility relative to target levels. Assessments should be carried out regularly, in increasing detail, during development and periodically throughout the propulsion system lite cycle.SAE ARP 1420C pdf free download.