We report on the construction and development of a broad‐spectrum vibrothermography (Sonic IR) measurement system at the Center for NDE. The new system uses a broadband actuator instead of an ultrasonic welder to generate vibration and induce heating of cracks. A high‐resolution infrared camera captures the IR signature of a crack, and a reconfigurable data acquisition software system acquires ...

This study reconstructed the flow field of a symmetrical variable inlet guide vane in centrifugal compressor through passive control method slots. Based on high-fidelity numerical simulation model verified by experiments, influence different slot forms was investigated, and mechanism revealed. The results demonstrated that can effectively suppress suction surface separation broaden range low-lo...

This paper describes a modeling method and a new optimal control approach to investigate a Mach number control problem for the NASA Ames 11-Foot Transonic Wind Tunnel. The flow in the wind tunnel is modeled by the 1-D unsteady Euler equations whose boundary conditions prescribe a controlling action by a compressor. The boundary control inputs to the compressor are in turn controlled by a drive ...

In the process of milling profile vanes a gas turbine engine on multi-operational machines, technological scheme transverse line shaping is used. According to this scheme, vane rotates around its own axis, it machined with mill spherical working surface, which performs rotation and interpolated axial movement. The required parameters surface quality airfoil (profile accuracy roughness parameter...

In Japan, the refrigerant used in room air-conditioners has been changed from HCFC-22 (R-22) to R-410A, a blend of HFC-32 and HFC-125 (50/50 vt%), in order to protect the ozone layer. Generally, the miscibility between the refrigerant and refrigeration oil must be assured, because the oil needs to return to the compressor from the refrigeration cycle and lubricate the sliding parts. Alternative...

In this work a response surface approach was used for predicting the hill chart of a small horizontal shaft Kaplan turbine. To this aim, artificial neural networks (ANN) were chosen as a fast, reliable, and computationally inexpensive tool. The training of the ANN was based on computational fluid dynamics (CFD). The optimization of the runner-guide vane stagger correlation is a time consuming a...

in this century due to population growth, the use of river water has become more complicated. since most rivers pass across loose and erodible areas, they always act as the most important factor of transferring eroded materials from the solid crust of the earth.  vortex basins are among the solutions known for the high-speed separation of solids from liquids (filtration). one of the problems of...