Experimental study of the hydrothermal characteristics of copper tube in the presence of the multi-string and multi-strip magnetic turbulator

Electromagnetic vibration (EMV) is a novel active method to enhance heat transfer in heat exchangers. This method installs a magnetic turbulator vibrating at a specific frequency inside a tube. Recent studies have used a single turbulator inside the tube. This paper is the first exploration of the effect of using multiple turbulator on hydrothermal parameters. In this regard, a turbulator with strip or string geometries with three different ar-rangements of double, triple, and quadruple turbulators was placed inside the tube to investigate its effect on heat transfer and pressure drop. Experiments were performed for the Reynolds number range from 500 to 1500. The results indicated the significant effect of the geometry and the magnetic turbulator arrangement on hy-drothermal parameters. The highest heat transfer and thermal enhancement factor (TEF) were observed in a quadruple strip turbulator. In the presence of this turbulator, heat transfer was up to 3.02 times that of the plain tube, and TEF was 2.01.