State of the Art in Sub-scale STOVL Hot Gas Ingestion Wind Tunnel Test Techniques

This paper presents a detailed summary of the JSF STOVL Hot Gas Ingestion (HGI) sub-scale test program. It focuses on the System Demonstration and Development (SDD) phase of the JSF Program, where significant advances in the fidelity of testing have been made. It documents the improvements and refinements made to the dedicated test facility and powered wind tunnel model required for HGI testing.

The paper covers an introduction to JSF and HGI, wind tunnel model hardware development, propulsion system calibrations, validation and understanding of the STOVL flow-field including comparison to full-scale data and test facility improvements.

These improvements are also given perspective as the paper explains their practical effect in increasing the fidelity and confidence in the sub-scale test data, which will ultimately be used to support flight clearance for the F-35B aircraft. The improvements in test efficiency enable a more comprehensive database to be gathered within a given time frame.