Reconfigurable Plenoptic Objective for Snapshot Multimodal Flow Diagnostics

Obtaining detailed flow measurements during a realistic hot-fire experiment is of the upmost importance for characterizing the complicated flow physics that occur during plume-surface interactions, and for providing high-fidelity data to the modeling community for code validation. The proposed research program will help close the information gap by advancing state-of-the-art optical techniques for measuring high-speed, high-temperature, chemically reacting plumes under full-scale test conditions. Nanohmics, Inc., working in partnership with the Stevens Institute of Technology, proposes to develop and demonstrate a modular imaging system for performing non-intrusive, time-resolved flow measurements for PSI test environments. The proposed system will include a reconfigurable plenoptic objective (i.e., photographic lens) that will convert a standard high-performance camera into a multispectral high dynamic range polarimetric imaging system. Customizations afforded by the plenoptic objective will allow end-users to configure the system for different quantities of interest by trading spatial resolution for dynamic range, spectral content, or polarimetric information. The system will include a set of standard configurations and post-processing algorithms to provide turn-key measurement capabilities for hot-fire plumes of propellants commonly used in Lunar and Mars landers (e.g., LOX/H2, LOX/LCH4, and hypergolic propellants), and include functionality for generating quantities of interest for comparison with computational fluid dynamics models. Low-cost implementations of the plenoptic objective will be scalable across a wide range of reduced- and full-scale ground test environment and systems, and may be used as a new standalone measurement system or as a component upgrade to existing measurement systems.