Numerical study of MHD pressure drop in rectangular ducts with insulating coatings

The MHD (magnetohydrodynamic) effect is a key issue, and quite often a constraint, in the development of liquid metal breeder blankets. The insulating coating is an effective approach to reduce the MHD effect. However, the insulating performance of coatings may be weakened by cracks caused by mechanical stresses, corrosion and so on. A three-dimensional code named MTC-H 1.0 was adopted to simulate the MHD flow in rectangular ducts with perfect and imperfect coatings. The results showed that perfect coatings could maintain the pressure drop to the level with fully electrically insulated wall when coating resistance was greater than 0.01, and longer crack distance (L) would lead to higher MHD pressure drop in the duct with imperfect coatings.