Experimental study of submerged liquid metal jet in a rectangular duct in a transverse magnetic field

Abstract

A liquid metal flow in the form of a submerged round jet entering a square duct in the presence of a transverse magnetic field is studied experimentally. A range of high Reynolds and Hartmann numbers is considered. Flow velocity is measured using electric potential difference probes. A detailed study of the flow in the duct's cross-section about seven jet's diameters downstream of the inlet reveals the dynamics, which is unsteady and dominated by high-amplitude fluctuations resulting from the instability of the jet. The flow structure and fluctuation properties are largely determined by the value of the Stuart number ${{N}}$ . At moderate ${{N}}$ , the mean velocity profile retains a central jet with three-dimensional perturbations increasingly suppressed by the magnetic field as ${{N}}$ grows. At higher values of ${{N}}$ , the flow becomes quasi-two-dimensional and acquires the form of an asymmetric macrovortex, with high-amplitude velocity fluctuations reemerging.

Time Domain, Frequency Domain, and Time–Frequency Domain Analysis of Axial Liquid Velocity Signals under the Influence of Internal Components

“…The analysis of the higher-order moments of the liquid velocity probability density distribution function consists mainly of the third moment (skewness) and the fourth moment (kurtosis), where skewness refers to the degree of asymmetry around the mean value and kurtosis measures the relative peak value concerning the normal distribution . The variation of skewness and kurtosis with operating conditions can characterize the magnitude and direction of liquid velocity fluctuations . In addition, kurtosis and skewness can also be used to obtain the critical flow transition conditions between laminar and turbulent flow .…”

“…15 The variation of skewness and kurtosis with operating conditions can characterize the magnitude and direction of liquid velocity fluctuations. 16 In addition, kurtosis and skewness can also be used to obtain the critical flow transition conditions between laminar and turbulent flow. 17 In frequency domain analysis, the power spectrum of the liquid phase is obtained by the fast Fourier transform (FFT) technique and the inertial range is usually found to follow the Kolmogorov −5/3 law.…”