A rotary vane expander has been developed to replace the throttling valve for improving the COP of transcritical CO2 refrigeration system. Due to the serious internal leakage, the expander efficiency is not satisfactory. This paper presents the theoretical and experimental investigation on the internal leakage in a rotary vane expander prototype. Firstly, the leakage flow rate through the inter...

We consider a two-dimensional convection model augmented with the rotational Coriolis forcing, centrifugal forcing as well as the quadratic potential V (x), ∂tU + (U − Ωx⊥) · ∇xU = −ΩU⊥−∇xV , with a fixed Ω > 0 being the rotational frequency. This model arises in the semiclassical limit of the Gross–Pitaevskii equation for Bose–Einstein condensates in a rotational frame. We investigate whether ...

In the cholesteric (Ch) phase, director rotates when temperature gradient is applied along its helical axis, which is called Lehmann rotation [1]. However, this phenomenon is poorly reproducible; the experimental verification for the Lehmann rotation isn !Gt enough yet. In this situation, recently, it was found the texture on the droplet formed by the Ch phase (Ch droplet) rotates under the tem...

a palatal defect may result from surgical resection, and its consequences could include difficulty in speech and nasal regurgitation of food and liquids. an obturator combined to speech aid prosthesis can improve nasal emission during speech,  and  assist  in  preventing  nasal  regurgitation  of  food.  this  article presents a clinical report of the reconstruction of palatopharyngeal function...

The paper shows the successive steps of approximation of Picard unification for the solution of the non-isothermal fluid flow in thin layer including inertia forces and apparent viscosities described by the non-linear dependences. In this paper is presented a unified semi analytical method of solution of the asymmetrical, laminar, steady and unsteady, non-Newtonian lubrication problem flow betw...

Transient direct current photoconductivity (TDCP) is an experimental technique capable of providing information about the sign and magnitude of differences in dipole moment, μ, for the ground state versus an excited state of an uncharged molecular chromophore in solution.2 Briefly, the technique utilizes a static, external electric field to achieve partial orientation of dipolar molecules, as s...

We study the 2D rotational compressible Euler equations with two singular parameters: the Rossby number for rotational forcing and the Froude/Mach number for pressure forcing. The competition of these two forces leads to a newly found parameter δ = τσ−2 that serves as a characteristic scale separating two dynamic regimes: δ 1 for the strong rotation regime [CT08] and δ 1 for the mild/weak rotat...

For some hydropower stations with longer pressurized pipelines, the by-pass pressure relief valves (PRVs) with an optimized coordinating control strategy are preferred to surge tanks for controlling transient pressures. Based on the method of characteristics, a simulation model of a hydro-mechanical system is built to connect the detailed flow characteristics of the PRV to a coordinating contro...

A one-channel time-reversal (TR) experiment is performed inside a rough reverberating cavity in the presence of a rotational flow. The amplitude of the TR wave is plotted versus the distance between the TR channel and the initial source: when they coincide, it exhibits a "time-reversal enhancement" (TRE). With no flow, the TRE is the same as the coherent backscattering enhancement (CBE). But co...

A computational analysis is performed on the diffraction of water waves induced by large-diameter, surface-piercing, vertical circular cylinder. With reference to linear-wave cases, the phenomenon is preliminarly considered in terms of velocity potential, a simplified theoretical framework in which both hypotheses of inviscid fluid and irrotational flow are incorporated. Then, and as a first-ap...