The entrance conditions for pulsatile flow are important in the understanding blood flow out of the heart and in developing regions at branches. The pulsatile entrance flow was solved using a spectral element simulation of the full unsteady Navier- Stokes equations. A mean Reynolds number of 200 and a range of Womersley parameters from 1.8 to 12.5 was used for a sinusoidal inlet flow waveform 1+sin (ωt). Variations in the entrance length were observed during the pulsatile cycle. The amplitude of the entrance length variation decreased with an increase in the Womersley parameter. The phase lag between the entrance length and the inlet flow waveform increased for Womersley parameter α up to 5.0 and decreased for α larger than 5.0. For low α, the maximum entrance length during pulsatile flow was approximately the same as the steady entrance length for the peak flow. For high α, the pulsatile entrance length was more uniform during the cycle and tended to the entrance length for the mean flow. The wall shear rate reached its far downstream value after only about half of the entrance length and also exhibited a dependence on α. The results quantify the entrance conditions typically encountered in studies of the arterial system.
Skip Nav Destination
Article navigation
August 1994
Research Papers
Unsteady Entrance Flow Development in a Straight Tube
Xiaoyi He,
Xiaoyi He
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405
Search for other works by this author on:
David N. Ku
David N. Ku
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405
Search for other works by this author on:
Xiaoyi He
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405
David N. Ku
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405
J Biomech Eng. Aug 1994, 116(3): 355-360 (6 pages)
Published Online: August 1, 1994
Article history
Received:
January 7, 1993
Revised:
September 28, 1993
Online:
March 17, 2008
Citation
He, X., and Ku, D. N. (August 1, 1994). "Unsteady Entrance Flow Development in a Straight Tube." ASME. J Biomech Eng. August 1994; 116(3): 355–360. https://doi.org/10.1115/1.2895742
Download citation file:
Get Email Alerts
Effect of Internal Mechanical Environment of Porous Scaffolds on Mechano-driven Bone Ingrowth: A Numerical Study
J Biomech Eng (September 2023)
In Silico Mechanical Effort Analysis of the All-On-4 Design Performed With Platform-Switching Distal Short Dental Implants
J Biomech Eng (September 2023)
Related Articles
Pulsatile Flow and Mass Transport Over an Array of Cylinders: Gas Transfer in a Cardiac-Driven Artificial Lung
J Biomech Eng (February,2006)
Blood Flow in Abdominal Aortic Aneurysms: Pulsatile Flow Hemodynamics
J Biomech Eng (October,2001)
Pulsatile Blood Flow and Gas Exchange Across a Cylindrical Fiber Array
J Biomech Eng (October,2007)
Application of Large-Eddy Simulation to the Study of Pulsatile Flow in a Modeled Arterial Stenosis
J Biomech Eng (August,2001)
Related Proceedings Papers
Related Chapters
Wall Shear Rates Induced by a Single Cavitation Bubble Collapse
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Introduction and Scope
High Frequency Piezo-Composite Micromachined Ultrasound Transducer Array Technology for Biomedical Imaging
Wavelet Analysis of Biomedical Time Series for Characterization of Blood Circulation Patterns and Human Health Status
Intelligent Engineering Systems through Artificial Neural Networks, Volume 16