Estimate of the pressure distribution for the nonlinear verigin problem in the two-dimensional radial case

1983 ◽  
Vol 18 (3) ◽  
pp. 466-468
Author(s):  
M. F. Karimov ◽  
R. K. Mukhamedshin
Author(s):  
Yutaka Asako ◽  
Kenji Nakayama

The product of friction factor and Reynolds number (f·Re) of gaseous flow in the quasi-fully developed region of a micro-tube was obtained experimentally and numerically. The tube cutting method was adopted to obtain the pressure distribution along the tube. The fused silica tubes whose nominal diameters were 100 and 150 μm, were used. Two-dimensional compressible momentum and energy equations were solved to obtain the flow characteristics in micro-tubes. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. The both results agree well and it was found that (f·Re) is a function of Mach number.


1963 ◽  
Vol 67 (632) ◽  
pp. 529-530 ◽  
Author(s):  
E. Angus Boyd

Recently some data from tests done on a cambered plate have been published. The shape of metal plate aerofoil tested matched that taken up by a flexible two-dimensional sail. The most striking result in the rneasurements was the waviness present near the leading edge in the upper surface pressure distribution. To find the theoretical conditions under which such a waviness would occur a parabolic skeleton aerofoil was investigated, as this shape differed little from the actual aerofoil tested.


Author(s):  
Jianghong Zhao ◽  
Xin Li

The vortex gripper is a kind of pneumatic noncontact gripper that does not produce a magnetic field and heat. It can grip a workpiece without physical contact, which avoids any unintentional damage such as mechanical scratches, local stress concentrations, frictional static electricity, and surface stains. This study focused on the two-dimensional pressure distribution field on a workpiece surface under the vortex gripper. Theoretical, experimental, and computational fluid dynamics results were combined to study the backflow phenomenon in the annular skirt, which can decrease the gripper’s suction force after the maximum value is reached. First, the pressure distribution in the annular skirt was theoretically modeled. A comparison with the experimental results showed that increasing the gap height between the gripper and workpiece generates a circumferentially asymmetrical flow field in the skirt. Based on this, it was hypothesized that an airflow in the circumferential direction may exist. The experimental data and simulation results were analyzed under large gap height conditions to observe the backflow in detail and it was found that an uneven pressure distribution with positive and negative pressure regions generated by the uneven flow is the root cause of the backflow. Finally, the effect of the backflow on the flow field in two different flow regions (in the annular skirt and inside the vortex chamber) was analyzed and the reason why the suction force of the vortex gripper has a maximum value was determined.


2003 ◽  
Vol 125 (1) ◽  
pp. 158-165 ◽  
Author(s):  
A. Ashrafizadeh ◽  
G. D. Raithby ◽  
G. D. Stubley

This paper describes a method for calculating the shape of duct that leads to a prescribed pressure distribution on the duct walls. The proposed design method is computationally inexpensive, robust, and a simple extension of existing computational fluid dynamics methods; it permits the duct shape to be directly calculated by including the coordinates that define the shape of the duct wall as dependent variables in the formulation. This “direct design method” is presented by application to two-dimensional ideal flow in ducts. The same method applies to many problems in thermofluids, including the design of boundary shapes for three-dimensional internal and external viscous flows.


Author(s):  
A. Uenishi

This paper deals with a hodograph method for design of turbine cascades in high subsonic flow and an approximate solution to a gas, specific heat ratio γ = −1 (the Karman-Tsien approximation) and γ > 1 (the gas obeying the adiabatic law). Numerical examples and a comparison of theoretical and measured pressure distribution for profiles designed by this method are given. Further, a better criterion for design to improve cascade efficiency is also presented.


Author(s):  
V. S. Beknev

The author compares three different approaches for generalization of experimental data for two-dimensional compressor cascades at low speeds: generalization for maximum value of lift-drag ratio, generalization for maximum cascade quality, and generalization for minimum loss coefficient. Some results given, of comparison for incidence and deviation angles, solidities, and loss coefficients, show the largest difference to be for incidence angles and loss coefficients. Influence of isentropic exponent on the airfoil pressure distribution and cascade losses is considered.


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