Abstract:To explore the key parameters of spray flow and fuel combustion characteristics under critical or supercritical pressure conditions in advanced engines, a novel TSCST experimental setup was developed. The main components include a mechanical structure and an integrated gas flow system, featuring several innovative designs: First, a shock dumper with multiple diffusion channels replaces the conventional single-pulse shock tube dump tank, effectively regulating secondary pressure rises caused by additional shock pulses. Second, leveraging shock wave dynamics theory, a three-dimensional converging structure with a specialized curved contour was constructed, substantially enhancing the intensity of the reflected shock wave. Third, an aerosol inlet end cap structure was designed to precisely control the injection of gas-phase fuels as well as low-saturation vapor pressure, high-boiling point, or multi-component complex liquid fuels. Finally, to reduce wall boundary layer effects, the shock tube features a large diameter of 210 mm for both driver and driven sections, making it one of the largest external chemical shock tubes nationwide. Extensive repeatability tests under single- and double-diaphragm conditions have validated the shock wave generation and enhancement capabilities of this setup. Results show that the large-diameter design produces near-ideal pressure profiles lasting up to 14.5 ms. The converging contraction section increases the Mach number of planar shock waves by a factor of 1.6. Additionally, the shock dumpers reduce the pulse pressure of secondary reflected shock waves by over 20% compared to traditional dump tank designs. Overall, this innovative shock tube system exhibits excellent performance in generating high-intensity shock waves while suppressing additional shock pulse effects, offering a powerful experimental platform for investigating high-pressure spray flow dynamics and fundamental combustion reaction kinetics.