Experimental measurement of void fraction in cryogenic two phase upward flow

✍ Scribed by A. Khalil; G. McIntosh; R.W. Boom

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 348 KB
• Volume: 21
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(81)90174-0

✦ Synopsis

Experimental measurements of the void fraction in two-phase single component upward flow of both helium and nitrogen were carried out using the capacitance probe technique. An electronic circuit was designed and constructed to accurately detect small changes in the dielectric constant resulting from changes in density in the two-phase flow. A coaxial capacitance probe at the exit of the test section was used as the sensing element to pick up changes in void fraction.

Tests ware carried out at both adiabatic and diabetic conditions on two test section sizes (6.35 and 2. 75 mm id and each 1000 mm long) with exit quality ranging from 0 to 100%, liquid flow of 5 to 351t7-I and inlet pressures of I to 2 attn. Analysis of the data indicates that the slip ratio (obtained from quality and void fraction measurements) is affected primarily by pressure, mixture quality, superficial velocity and to a lesser degree by the size of the test section.

The data of helium and nitrogen is also compared with the predictions of Lockhart-Martinelli, Levy and the homogeneous models.