Failure to comply with the performance test requirements for the centrifugal pumps at power plants often results in performance dissatisfaction as a result of field tests. This study proposed a method of reducing the uncertainty of the field test results by evaluating the systematic error in the measurement system caused by failure to follow the test requirements using the computational fluid dynamics(CFD) technique. As a result of the evaluation of the systematic error and reflecting it in the performance test data, it was confirmed that the error occurred at a constant rate with respect to the flowrate and that the pump, which showed a difference in performance actually had the same performance.

The objective of this study is to supply basic data for large reservoir sedimentation research in future and make suggestions to maintain and operate the reservoir more efficiently. At first, previous studies about the estimation of sediment yield rate were reviewed in Korea. And the discharge rating curves of upstream stage gauging stations and the correlation between dam inflow and stage discharge were analyzed. With the analysis results, the specific sediment rate of Soyanggang dam was estimated as 608 ^m3/㎢/yr It was similar to that of Soyanggang dam feasibility study and 1994`s field surveys of the reservoir than that of 1983`s field surveys. Because the sediment rating curves were derived under the low discharge conditions, it needs to be checked under the flood conditions. However, the suggested methods such as flowrate analysis and sediment estimation will be useful to the sediment studies in future.