Experimental investigation on the convection heat transfer enhancement for heated cylinder using pulsated flow

Gaheen, Osama A.; Benini, Ernesto; Khalifa, Mohamed A.; El-Salamony, Mostafa; Aziz, M. A.

doi:10.1016/j.tsep.2021.101055

Cited by 4 publications

(2 citation statements)

References 29 publications

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“…The pulsating flow was generated at 3 Hz. The experimental system consists of a double-acting pneumatic cylinder, 3/5 directional control valve solenoid operated with high-speed solenoid, air compressor, pressure regulator, easy scope, pulse generation circuit with classic control circuit [23], meter data logger for airflow, and air pressure data logger. Figure 4A-C shows the experimental system setup.…”

Section: Validation Of Automation Studio Simulationmentioning

confidence: 99%

Speed and torque control of pneumatic motors using controlled pulsating flow

Aziz

Benini

Elsayed

et al. 2023

Int J Adv Manuf Technol

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Pneumatic motors have several advantages and have many robotics and automation applications. The importance of the study is that it is a cheap and possible way to apply it to the fixed displacement pneumatic motors with simple directional control valve used. The purpose of the addition to any traditional pneumatic motors is to change the fixed displacement pneumatic motor to be variable speed and torque compared to the expensive systems such as the proportional control valve in many industrial applications. The study also included validated simulations using the Automation Studio program to control the pneumatic motor’s speed and torque. In addition, the results showed remarkable success in controlling the pneumatic motor outputs depending on the frequency of the compressed air-source pulses and pressure. The pulsating air frequencies of 1.5, 3, and 4.5 Hz were considered at different inlet source pressure changes from 1.72, 3.45, and 5.17 bar. As the pulsating flow frequency of compressed air decreased from 4.5, 3, and 1.5 Hz, the motor pressure and torque decreased. Furthermore, empirical correlations related to frequency and pressure effect have been developed. The error is 6.3–9.5% in predicting the motor speed and torque outputs. The limitation of the proposed method in real-life applications is about a maximum of 7.5 bar. On the other hand, the frequency is limited to 9 Hz using a mechanical solenoid.

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Section: Validation Of Automation Studio Simulationmentioning

confidence: 99%

Speed and torque control of pneumatic motors using controlled pulsating flow

Aziz

Benini

Elsayed

et al. 2023

Int J Adv Manuf Technol

Self Cite

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“…Gaheen, O. A. et al [14] conducted an experimental study to investigate convection heat transfer enhancement from a circular cylinder in laminar pulsating flow with pulsating frequency from 1Hz to 12 Hz and Re from 1.02 10 4 to 2.04 10 4 . Abdelhamid et al, [15] introduced a numerical simulation for an isothermal curved cylinder with a corner radius ratio r/R (= 0.5), attack angle (α) varies between 0° ≤ α ≤ 45° at low Reynolds number Re (= 180).…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of steady and pulsating flow over an isothermal cylinder with varying corner radius

Rahma,

Abdelhamid

2024

Menoufia Journal of Electronic Engineering Research

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This paper presents a numerical simulation of the flow structure, flow topology, and heat transfer of an isothermal cylinder with variable corner radius ratio (r/R) = 0, 0.1, 0.25, 0.5, 0.75, and 1.0, for two different flow regimes. One is steady and the other is pulsating flow. Here, r is the corner radius and R is the cylinder half-width. The air stream flow has a low Reynolds number Re of 100 and Prandtl number Pr = 0.7. The dimensionless amplitude of the velocity oscillations (A * ) is 40% relative to the free-stream velocity, and the dimensionless frequency is 7. The governing equations were solved using the ANSYS-FLUENT 19.2 package. The Pressure implicit with the splitting of the operator algorithm PISO is used for the pressurevelocity coupling. The results from the models agree with those in the literature. The effect of r/R on the flow structure around the cylinder is investigated for steady and pulsating flow regimes. Increasing r/R leads to the appearance of two major flow patterns around the cylinder. Pattern A appears at r/R < 0.1, which has leading-corner separation and two secondary bubbles appear on the sides of the cylinder. Pattern B appears at r/R ˃ 0.1, which has trailing-corner separation. The time-mean drag coefficient ( D ) for the pulsating flow is higher than that of the steady flow overall r/R. For the pulsating flow, D increases by about 5.37% overall r/R. The surface-and time-averaged Nusselt number increases with increasing r/R for both flow regimes.

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