Experimental investigation of pressure drop in structured packings

2012 ◽  
Vol 73 ◽  
pp. 285-298 ◽  
Author(s):  
Ali Zakeri ◽  
Aslak Einbu ◽  
Hallvard F. Svendsen
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Structured Packings

Experimental Investigation of Effect of Tip Coolant Ejection on Internal Flow Characteristics Within a Realistic Blade Coolant Channel

2013 ◽  
Author(s):  
Jian Pu ◽  
Zhaoqing Ke ◽  
Jianhua Wang ◽  
Lei Wang ◽  
Hongde You
Keyword(s):  
Experimental Investigation ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Turbine Blade ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Flow Ratio ◽  
Lp Turbine ◽  
Mass Flow Ratio

This paper presents an experimental investigation on the characteristics of the fluid flow within an entire coolant channel of a low pressure (LP) turbine blade. The serpentine channel, which keeps realistic blade geometry, consists of three passes connected by a 180° sharp bend and a semi-round bend, 2 tip exits and 25 trailing edge exits. The mean velocity fields within several typical cross sections were captured using a particle image velocimetry (PIV) system. Pressure and flow rate at each exit were determined through the measurements of local static pressure and volume flow rate. To optimize the design of LP turbine blade coolant channels, the effect of tip ejection ratio (ER) from 180° sharp bend on the flow characteristics in the coolant channel were experimentally investigated at a series of inlet Reynolds numbers from 25,000 to 50,000. A complex flow pattern, which is different from the previous investigations conducted by a simplified square or rectangular two-pass U-channel, is exhibited from the PIV results. This experimental investigation indicated that: a) in the main flow direction, the regions of separation bubble and flow impingement increase in size with a decrease of the ER; b) the shape, intensity and position of the secondary vortices are changed by the ER; c) the mass flow ratio of each exit to inlet is not sensitive to the inlet Reynolds number; d) the increase of the ER reduces the mass flow ratio through each trailing edge exit to the extent of about 23–28% of the ER = 0 reference under the condition that the tip exit located at 180° bend is full open; e) the pressure drop through the entire coolant channel decreases with an increase in the ER and inlet Reynolds number, and a reduction about 35–40% of the non-dimensional pressure drop is observed at different inlet Reynolds numbers, under the condition that the tip exit located at 180° bend is full open.

scholarly journals Adapting the Forchheimer equation for the flow of air through wheat straw beds

2016 ◽  
Vol 20 (suppl. 2) ◽  
pp. 463-470
Author(s):  
Djordjije Doder ◽  
Biljana Miljkovic ◽  
Borivoj Stepanov ◽  
Ivan Pesenjanski
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Wheat Straw ◽  
Measurement Methods ◽  
High Flow ◽  
Biomass Combustion ◽  
Inertial Effects ◽  
Forchheimer Equation ◽  
Flow Rates ◽  
Straw Bale

The paper presents the results of an experimental investigation of air pressure drop while flowing through wheat straw beds. According to Darcy?s law, the smaller the porosity of the bed is, the bigger the pressure drop will be. The investigation was conducted using three different porosities (or three bed densities), and for two different air flow rates. After determining porosity (which is directly measurable), the permeability of straw could be found. For high flow velocities, such as the velocity of air flowing through a straw bale, the Forchheimer equation becomes more relevant as a correction of Darcy?s law with inertial effects included. Otherwise, the permeability tensor depends only on the geometry of the porous medium. With permeability known, the Forchheimer equation coefficients can be easily estimated. These results may be important for the future development of efficient biomass combustion facilities. The measurement methods and facility characteristics are described in more detail.

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