Gallery

High-G two-phase Flow

Artificial gravity by rotation is an important method for controlling gas-liquid interaction and engineering multi-phase processes in space. As an example, in the Centrifugal Nuclear Thermal Rocket (CNTR), propellant gas is forced to penetrate through a liquid-state nuclear fuel and therefore receive heat. In such scenarios, knowledge of the bubble morphology, void distribution, and onset of entrainments is essential for analyzing heat transfer, neutronics, and design limits. 

RTHL provides relevant experimental benchmark and data for 1) testing the scalability of existing correlations with respect to extreme body forces, 2) evaluation of additional Coriolis effects, 3) validation of simulation models, and 4) accumulation of operational experience. Credits are given to MAE machinists Chad and Kevin for bring this from a design to the real world. 

• Switzer, G., & Zhang, T. (2026). Experiment on Bubbles Rising through a Shallow Pool under Artificial Gravity. 2026 ANS Annual Conference, Denver, CO, United States. 

TWO-phase flow measurement

Gas-liquid two-phase flow is inherently challenging to describe, model, and measure, due to the dynamic presence of interfaces forming complex multi-scale structures. It is however a critical engineering component for many applications such as chemical process control, species transportation, and heat and mass transfer. The limited knowledge and prediction capability on two-phase flow is one of the most pronounced uncertainties in nuclear reactor engineering. 

RTHL conducts in-house fabrication of several instruments for measuring gas-liquid two-phase flow. The photo above illustrates a four-sensor conductivity probe crafted by Dr. Zhang for demonstration purpose. This probe has a 1/16" casing comparable to miniature armored thermocouples. It houses four needle sensors capable of measuring void fraction, gas velocity, interfacial-area concentration, and other two-phase parameters. This design was proven robust in actual applications up to 180 deg C, 10 atm, within boiling water environment, at MTDL of UIUC where Dr. Zhang earned his PhD.