Experimental investigation on heat transfer of a specific fuel (RP-3) flows through downward tubes at supercritical pressure

摘要

The heat transfer characteristics of a specific hydrocarbon fuel RP-3 flowing through vertically downward miniature tubes (d_(in) = 1.8 mm) were experimentally investigated at supercritical pressure (P= 5 MPa, P_R=2.15) based on measured thermophysical properties under the fuel temperature ranged from 373 to 800 K. Test results indicated that: in the initial heating region, wall temperature increased dramatically from the initial heating point and then decreased rapidly at higher heat flux, but this phenomenon diminished when the inlet Reynolds number reached to 10,000. In addition, heat transfer deterioration occurred when thermal acceleration parameter (K_v) was less than 1.5 × 10~(-8) or buoyancy factor (Bo~*) was less than 1.6 × 10~(-10). Finally, a new heat transfer correlation was developed based on the experimental data and which predicted the heat transfer for RP-3 well.