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• Cascaded Bowknot-type taper based Mach–Zehnder interferometer (MZI) could be used for microfluidic flow rate detection. • The proposed sensor is suitable for liquids with refractive indexes ranging from 1.33 to 1.43. • The detectable water flow rate ranges from 0.66 mm/s to 10.6 mm/s. In microfluidic chip applications, the flow rate plays an important role. Here we proposed a simple liquid flow rate sensor by using two cascaded bowknot-type tapers (BTTs) to form a Mach–Zehnder interferometer (MZI) as the sensing element. As the water flows in the vicinity of the BTT, the cascaded BTTs based MZI's interference spectrum changes due to its contact with water. By comparing the time-swept spectra of the cascaded BTTs MZI from the state of one BTT in water to that of another BTT in water as the water flowing over it, the flow rate can be detected. The proposed sensor has a detectable range from 0.66 mm/s to 10.6 mm/s. [ABSTRACT FROM AUTHOR]

In this paper, the radial electromagnetic force and vibroacoustic behaviour of a switched reluctance motor (SRM) are predicted and analysed in detail. First, the radial force with the spatial–temporal distribution characteristics is derived analytically and verified by the 2D Fourier transform. Second, a multiphysics model, which not only includes the electromagnetic field, the mechanical field, and the acoustic field, but also takes into account the structural orthotropy and the non-uniformly distributed electromagnetic force, is established to predict the electromagnetic vibration and noise of a SRM. Third, based on the spatial and temporal orders of the force harmonics, the vibroacoustic mechanism of a SRM is revealed. Finally, the electromagnetic force and vibration under two control strategies, which include the angle position control (APC) and the current chopping control (CCC), are compared and analysed, respectively. The results show that the electromagnetic vibration and noise of a three-phase 12/8 SRM are mainly caused by the force harmonics with the spatial order of 4 and the temporal orders of 3 N 0 ± 1 (N 0 = 0, 1, 2···). Besides, under the two control strategies, the orders of the electromagnetic force and vibration are the same, but the amplitudes are different. [ABSTRACT FROM AUTHOR]