The effect of the tip gap size on the performance of a multistage axial compressor was studied by means of computational fluid dynamics (CFD). It was found that the performance of the compressor was very sensitive to the size of the tip gap. By increasing the gap size, the stall margin value, the total pressure ratio and the compressor efficiency reduced considerably. The flow field at the tip ...

An experiment was conducted in a linear cascade of Pak-B blades for an exit Mach number of 0.3 to simulate the flow in the tip-gap region of a low pressure turbine blade row. The experiment focused on the independent effects of thickness-to-gap and gapto-chord ratios on the tip-gap flow behavior. Two extreme gap-to-chord ratios of 5% and 8% were chosen, for which four thickness-to-gap ratios we...

The effects of tip-gap size on the tip-leakage vortical structures and velocity and pressure fields are investigated using large-eddy simulation, with the objective of providing guidelines for controlling tip-leakage cavitation and viscous losses associated with the tip-leakage flow. The effects of tip-gap size on the generation and evolution of the end-wall vortical structures are discussed by...

It is desirable to further increase the efficiency of turbo machines. In axial flow gas turbine, imprecise axial gap and tip clearance are two significant sources of inefficiency. This work investigates the effect of change in parameters such as axial gap and tip clearance on axial flow gas turbine used in power generation. Different combinations of axial gap and tip clearance have been tested ...

OBJECTIVES The characteristics of the megameatus intact prepuce (MIP) hypospadias variant present a unique challenge to surgeons. Dissatisfaction with the results of conventional repair methods led to the emergence of several alternative surgical approaches, including the glanular approximation (GAP) and pyramid procedures. The application of tubularized, incised plate (TIP) urethroplasty has n...

The fluctuations of the position of monatomic steps on Ag (111) are investigated by Scanning Tunneling Microscopy (STM). We analyze the influence of tip-sample interact~on by varying the gap ~mpedance over more than two orders of magnitude. For tunneling tips providing a weak tip-sample interact ion, we show that the step position au~ocorrelation function remains essentially unaltered. In this ...

Tip vortex cavitation is one of well known patterns of cavitation phenomenon which occurs in axial pumps. This pattern of cavitation occurs due to pressure difference between the pressure and suction sides of blades of an axial pump. Since the pressure in the pressure side of the blade is higher than the pressure in its suction side, thus a very small portion of liquid flow flows back from pres...

We have studied charge transfer through alkanethiol molecules self-assembled on Au(111) substrates using interfacial force microscopy. Simultaneous measurement of the tip-substrate current and the normal interfacial force reveals the critical role of tip-film contact. Measurable currents are seen only for tip-applied stresses above about 20 MPa, after which the current rises exponential with st...