TY - JOUR
T1 - Pressure drop reduction phenomenon of slush nitrogen flow in a horizontal pipe
AU - Ohira, Katsuhide
N1 - Funding Information:
This study was financially supported by JSPS under Grant-in-Aid for Scientific Research (B) No. 21360091.
PY - 2011/7
Y1 - 2011/7
N2 - Cryogenic slush fluids, such as slush hydrogen and slush nitrogen, are two-phase single-component fluids containing solid particles in a liquid. Their density and refrigerant capacity are greater than those of a liquid-state fluid alone. Owing to these advantages, there are high expectations for use of slush fluids in various applications such as a clean-energy fuel, fuel for space-planes to improve the efficiency of transportation and storage, and as a refrigerant for high-temperature superconducting power machines. Experimental tests were performed with slush nitrogen to obtain the frictional pressure drop flowing in a horizontal pipe with an inner diameter of 15 mm and a length of 400 mm. The primary objective of the study was to investigate the pressure drop reduction phenomenon according to changes in velocity and solid fraction. The pressure drop correlation between the friction factor and the Reynolds number was obtained, and an empirical correlation between them was derived. The flow pattern for slush nitrogen inside a pipe and the behavior of solid particles were observed using a high-speed video camera and the PIV method. From the experimental results, the pressure drop reduction phenomenon emerged clearly when the flow velocity was higher than 3.6 m/s and the flow pattern of solid particles inside the pipe was pseudo-homogeneous.
AB - Cryogenic slush fluids, such as slush hydrogen and slush nitrogen, are two-phase single-component fluids containing solid particles in a liquid. Their density and refrigerant capacity are greater than those of a liquid-state fluid alone. Owing to these advantages, there are high expectations for use of slush fluids in various applications such as a clean-energy fuel, fuel for space-planes to improve the efficiency of transportation and storage, and as a refrigerant for high-temperature superconducting power machines. Experimental tests were performed with slush nitrogen to obtain the frictional pressure drop flowing in a horizontal pipe with an inner diameter of 15 mm and a length of 400 mm. The primary objective of the study was to investigate the pressure drop reduction phenomenon according to changes in velocity and solid fraction. The pressure drop correlation between the friction factor and the Reynolds number was obtained, and an empirical correlation between them was derived. The flow pattern for slush nitrogen inside a pipe and the behavior of solid particles were observed using a high-speed video camera and the PIV method. From the experimental results, the pressure drop reduction phenomenon emerged clearly when the flow velocity was higher than 3.6 m/s and the flow pattern of solid particles inside the pipe was pseudo-homogeneous.
KW - Hydrogen energy
KW - Pressure drop reduction
KW - Slush hydrogen
KW - Slush nitrogen
KW - Two-phase flow
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U2 - 10.1016/j.cryogenics.2011.04.001
DO - 10.1016/j.cryogenics.2011.04.001
M3 - Article
AN - SCOPUS:79957442323
VL - 51
SP - 389
EP - 396
JO - Cryogenics
JF - Cryogenics
SN - 0011-2275
IS - 7
ER -