Mass Flow Rate Controlled Fully Developed Laminar Pulsating Pipe Flows

2005 ◽  
Vol 127 (3) ◽  
pp. 405-418 ◽  
Author(s):  
S. Ray ◽  
B. Ünsal ◽  
F. Durst ◽  
Ö. Ertunc ◽  
O. A. Bayoumi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Knowledge Flows ◽  
Experimental Investigations ◽  
Pipe Flows ◽  
Numerical Studies ◽  
Clear Insight ◽  
Rate Controlled ◽  
Number Of Publications

Pressure gradient driven, laminar, fully developed pulsating pipe flows have been extensively studied by various researchers and the data for the resultant flow field are available in a number of publications. The present paper, however, concentrates on related flows that are mass flow driven, i.e., the flows where the mass flow rate is prescribed as ṁ=ṁM+ṁAfm(t) and fm(t) is periodically varying in time. Sinusoidal and triangular mass flow rate pulsations in time are analytically considered in detail. Results of experimental investigations are presented and are complemented by data deduced from corresponding analytical and numerical studies. Overall, the results provide a clear insight into mass flow rate driven, laminar, fully developed pulsating pipe flow. To the best of the authors’ knowledge, flows of this kind have not been studied before experimentally, analytically and numerically.

scholarly journals INVESTIGATION OF COUNTER-CURRENT FLOW LIMITATION FOR AIR-WATER IN A PWR HOT LEG EXPERIMENTAL LOOP FOR DIFFERENT GEOMETRY

2020 ◽  
Vol 5 (2) ◽  
pp. 198-212
Author(s):  
Youssef Morghi ◽  
Jesus Puente ◽  
Amir Mesquita ◽  
Ana Baliza
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Water Mass ◽  
Experimental Investigations ◽  
Countercurrent Flow ◽  
Flow Limitation ◽  
Pressurized Water ◽  
Water Mass Flow Rate ◽  
Limiting Condition

Gas/liquid two-phase stratified flows in horizontal channels are frequently encountered in nuclear reactors, oil and gas pipelines, steam generators, refrigeration equipment, reflux condensers, packed columns, and heat pipes. The phenomenon known as countercurrent flow limitation, or flooding, is the limiting condition where the flow rates of neither the gas nor the liquid can be further increased without changing the flow pattern. This is the condition where the maximum air mass flow rate at which the down-flowing water mass flow rate is equal to the inlet water mass flow rate. This limiting condition, also known as onset of flooding, can occur in vertical or horizontal geometry. This work is a review of recent experimental investigations of countercurrent flow limitation (CCFL) for various hot-leg geometries of pressurized water reactors (PWRs). We compare results with those obtained from the Nuclear Technology Development Centre (CDTN) in 2005. Recent experimental results in the literature are in good agreement with the 2005 findings.

The Experimental Investigations of Centripetal Air Bleed With Tubed Vortex Reducer for Secondary Air System in Gas Turbine

2014 ◽  
Author(s):  
Xiao Chen ◽  
Ye Feng ◽  
Lijun Wu
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Experimental Investigations ◽  
Pressure Losses ◽  
Nozzle Guide

In a modern gas turbine, the air bled through High Pressure Compressor (HPC) rotor drums from the main flow is transported radially inwards and then transferred to cool the High Pressure Turbine (HPT). The centripetal air flow creates a strong vortex, which results in huge pressure losses. This not only restricts the mass flow rate, but also reduces the cooling air pressure for down-stream hot components. Adding vortex reducer tubes to the centripetal air bleed can reduce the pressure loss and ensure the pressure and mass flow rate of the supply air. Design optimization of the tubed vortex reducer is essential in minimizing the pressure losses. This paper describes experimental investigations of different configurations of tubed vortex reducers at different rotational speeds and mass flow rates. Particular attention is paid to the shape of the drum hole, the length of the tubed vortex reducers at the same installation location, and the angles of the nozzle guide vane outlets. The core section of test rig is comprised of two steel disks, one drum rotor and stationary cases with nozzle guide vanes. It operates at representative engine parameters, such as the turbulent flow parameter, λT(0.2–1.8) and the Rossby number Ro(0.05–0.08). Three conclusions can be drawn based on the experimental results. 1) The shape of the drum hole is a key factor of the bleed system pressure loss. An oval hole configuration has less flow resistance and results in lower pressure losses compared with a circular hole design. 2) The tests prove that tubed vortex reducers are instrumental in minimizing centripetal air flow. These components effectively restrain the free vortex development and decrease the pressure losses in the cavity. 3) Basically, the flow field consists of a free vortex and a forced vortex. The length of the tube influences the flow field and the pressure losses at the inlet and outlet of the tubed vortex reducer. However, the tube length is less important when compared with the shape of drum hole.

Experimental investigations on jet impingement solar air collectors using pin-fin absorber

2020 ◽  
pp. 095440892093530 ◽  
Author(s):  
C Kannan ◽  
M Mohanraj ◽  
P Sathyabalan
Keyword(s):  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Jet Impingement ◽  
Climatic Conditions ◽  
Solar Irradiation ◽  
Experimental Investigations ◽  
Air Mass ◽  
Pin Fin

In this paper, the performances of a novel jet impingement solar air collector (JISAC) using flat and pin-fin absorbers were experimentally investigated. The experimental observations in a JISAC have been made under the climatic conditions of Coimbatore city in India during the year 2019. The thermo-hydraulic analyses were conduced to study the influence of pressure drop across the perforated jet plate. The effects of solar irradiation, ambient temperature, ambient wind velocity and air mass flow rate through the JISAC duct using flat and pin-fin absorbers were studied. The air mass flow rate through the JISAC was optimized to 0.025 kg/s based on the experimental trials. Thermodynamic performance comparisons have been made among the flat and pin-fin absorbers. The results showed that, the JISAC using pin-fin absorber has 2–7°C higher air temperature at the outlet with 3–7%, 2–6% and 2–6% improved energy efficiency, thermo-hydraulic efficiency and exergy efficiency, respectively when compared to the JISAC using flat absorber. The pressure drop across the JISAC duct is about 90% higher when compared to the conventional solar air collectors. The pressure drop through the jet plate has increased the air velocity impinging on the absorber. As a result, the heat transfer coefficient between air and the absorber has been significantly improved.

The standard unit mass flow rate of gas-liquid mixtures

2020 ◽  
pp. 13-16
Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Liquid Mixtures ◽  
Unit Mass ◽  
Standard Unit
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