Variation of average velocity through the transition pipes at cross sections perpendicular to the axis

Abstract

Transition ducts are used in water channel and wind tunnels, turbomachinery, especially aircraft air intakes and power station ducting systems. Due to significant energy losses, flow through these ducts are very important. Inlet and outlet sections of transition ducts may be equal or different as well as their positions. In this study, the variations of average velocity have been investigated in ideal cases where the transitions are based on straight-line generators from a point at one end to the corresponding at the other. Variations of the average velocity along the transition duct have been calculated for all transition types. The variations of the velocity along the axes observed that it depends only on inlet and outlet cross sectional shapes and their positions. The transition between equal sections having different inlet and outlet shape, eg, from a circular section to a square section, it has been observed that the velocity value vx decreases through the hallf of the duct length and increases to the inlet value at the outlet section. At the same time, the velocity variation in linear state have been investigated for every transition type.

Transition ducts are used in water channel and wind tunnels, turbomachinery, especially aircraft air intakes and power station ducting systems. Due to significant energy losses, flow through these ducts are very important. Inlet and outlet sections of transition ducts may be equal or different as well as their positions. In this study, the variations of average velocity have been investigated in ideal cases where the transitions are based on straight-line generators from a point at one end to the corresponding at the other. Variations of the average velocity along the transition duct have been calculated for all transition types. The variations of the velocity along the axes observed that it depends only on inlet and outlet cross sectional shapes and their positions. The transition between equal sections having different inlet and outlet shape, e.g. from a circular section to a square section, it has been observed that the velocity value vx decreases through the half of the duct length and increases to the inlet value at the outlet section. At the same time, the velocity variation in linear state have been investigated for every transition type.