Flow characteristics of V-Cone flowmeter in wet steam
Wet steam is a common two-phase flow whose mass flow-rate can be measured by V-Cone flowmeter. The mass flow coefficient CD of V-Cone is no longer approximately constant which affects the measuring accuracy subject to the complex flow characteristics of wet steam and discrete droplets. Firstly, five main impact factors for CD of V-Cone were obtained by dimensional analysis, namely, vapor Reynolds number, liquid-vapor density ratio, mass loading ratio, potential to kinetic energy ratio and dimensionless droplet diameter respectively. Then CFD simulation was carried out to study the influence of these parameters. Eulerian multiphase model and SST k-ω turbulence model were adopted for steady simulation. The simulation results coincided well with the experimental results. The results indicate that CD is almost not affected by vapor Reynolds number and potential to kinetic energy ratio; it increases with the liquid-vapor density ratio, mass loading ratio and dimensionless droplet diameter, among which mass loading ratio is the main factor.
Two-phase mass flow coefficient of V-Cone throttle device
The V-Cone throttle device has been paid more and more attentions on the measurement of the wet gas flow in recent years. However, it tends to over-read the gas flow rate when directly used to measure the wet gas. How to correct this over-reading and obtain an accurate yet simple wet gas correlation is still one of the challenges in the investigation on the V-Cone throttle device. In this paper, the two-phase mass flow coefficient of the V-Cone throttle device was proposed to correct the deviation of the readings produced by the device. The parameters affecting the coefficient were determined and discussed experimentally. Two V-Cone throttle devices with the respective equivalent diameter ratios of 0.65 and 0.75 were investigated under the condition of the wet gas flow. The test fluid was air and tap water. The gas-to-liquid density ratio ranged from 0.002445 to 0.006083, and the gas densiometric Froude number ranged from 0.3 to 2.0. The influencing parameters including the Lockhart–Martinelli parameter, the gas-to-liquid density ratio, the gas densiometric Froude number and the equivalent diameter ratio were studied. Then the correlations of the two-phase mass flow coefficient and the influencing parameters were proposed for the two V-Cone throttle devices and evaluated experimentally. The results show that the relative deviations of the correlations are less than ±5.0% and the average deviations of the correlations are 2.06% and 2.22% for the V-Cone throttle devices with the equivalent diameter ratio of 0.65 and 0.75, respectively. It can be concluded that the two-phase mass flow coefficient of the V-Cone throttle device is crucial for the development of the wet gas correlation.
Code switching in Ahdaf Soueif's The Map of Love
This article examines the phenomenon of code switching in The Map of Love (1999) by the Egyptian—British writer Ahdaf Soueif. Though she chooses English as a medium for her creative expression, Soueif deploys Arabic in her narrative to represent different aspects of the linguistic and cultural norms of Egyptian society. The article's methodology is informed by Kachru's framework on contact literature and his categorization of the occurrence of literary code switching or bilingual creativity into different strategies that encompass cultural and linguistic processes. The results indicate the predominance in The Map of Love of the discourse strategies of employing lexical borrowing, culture-bound references and translational transfer. Finally, the article analyzes the functional motivation of code switching in the postcolonial context of the novel and how the use of certain creative strategies might enhance or diminish the narrative's effectiveness and readability.