A NEW METHOD FOR FORMING THE STRUCTURE OF THE NUTATION LINE IN NUCLEAR MAGNETIC FLOWMETERS-RELAXOMETERS FOR DIFFERENT FLOW MODES OF LIQUID MEDIA

The problems that arise when monitoring flow parameters (flow rate, relaxation times, Reynolds number) using the nuclear magnetic resonance method at a rapid change in the flow speed in a turbulent flow regime are considered. A new method has been developed for forming the structure of a nutation line with magnetization at the level of noise from the liquid medium flow in a strong inhomogeneous magnetic field. Experimental studies of the nutation line formed from the flow of magnetized liquid were carried out for its various parameters. The adequacy of using the new method for measuring the fluid flow q and longitudinal relaxation time T1 in a current flow has been confirmed. New coefficients are proposed in the Bloch equations, which describe the movement of three magnetization components (Mx', My', and Mz') in a nutation coil in a fluid flow in a strong inhomogeneous field. For various parameters of the magnetic fields and fluid flow, the structures of the nutation line are calculated, which correspond to the experimental ones. The experimental and theoretical data obtained made it possible to establish the relationship between the parameters of magnetic fields and the flow velocity (the duration of action of a radiofrequency field on the magnetized liquid in the section of the pipeline, on which the nutation coil is located) to ensure the formation of the nutation line at the noise level.