Frequency response function method with constraint efficiency factors for Hot/Cold spot problems

Kasahara, Naoto

Temperature fluctuation from incomplete fluid mixing induces typically bending plus peak stress across wall thickness. For this stress mode, author has developed the frequency response function to establish design-by-analysis methodology for this phenomenon. On the other hand, it is pointed out that hot and cold spots appear near T-junctions in piping systems, Those induce other stress modes from three-dimensional temperature distributions. This report describes the extension of the frequency response method to hot and cold spot problems by introducing constraint efficiency factors. Its applicability was validated by application to a hot spot near the T-junction of PHENIX secondary piping system.