One-dimensional modelling and simulation of multiple solution characteristics of hydrocarbon fuel flow excursion in scramjet parallel cooling channels

To investigate flow excursion of hydrocarbon fuel in parallel cooling channels of the scramjet, one-dimensional steady-state model of hydrocarbon fuel flow and heat transfer in parallel channels is developed and validated. Flow excursion occurs in the negative slope region of the fuel hydrodynamic curve. Multiple solutions (stable and unstable ones) of flow and temperature distributions are presented. Further simulations are developed at the pressure of 2.2–7.0 MPa, heat flux of 0.5–3.0 MW/m². Influencing factors such as back pressure, hot resistance, heat flux, thermal deviation and parallel channels number are studied. Higher back pressure affects the fuel properties and negative slope of hydrodynamic curve disappears, which restrains the flow excursion. Hot resistance presents a non-monotonic influence on flow excursion. Hot resistance that is too large or too small suppresses flow excursion. Higher heat flux magnifies the flow excursion amplitude and narrows the flow range of multiple solutions. When channel number increases, the feature of multiple solutions is much more complex and the flow excursion modes becomes tricky.