Previous investigators have used the steady Bernoulli equation to correct the underestimation of alveolar pressure by airway pressure observed during unsteady flow conditions. Using a simple idealized geometry, we demonstrate a method of including the unsteady term of the Bernoulli equation. Our approach was to determine the axial velocity distribution from the wave equation and employ this solution with the unsteady Bernoulli equation. In addition, we estimate the importance of inertia and viscosity and show that these effects can be quantified by the Womersley number.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0034-5687(89)90072-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Explicit travelling wave solutions to the time fractional Phi-four equation and their applications in mathematical physics.
Sci Rep
January 2025
Department of Mathematics and Statistics, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.
In applied research, fractional calculus plays an important role for comprehending a wide range of intricate physical phenomena. One of the Klein-Gordon model's peculiar case yields the Phi-four equation. Additionally, throughout the past few decades it has been utilized to explain the kink and anti-kink solitary waveform contacts that occur in biological systems and in the field of nuclear mechanics.
View Article and Find Full Text PDFIntravascular ultrasound-derived virtual fractional flow reserve in the superficial femoral artery.
CVIR Endovasc
December 2024
Department of Cardiovascular Medicine, Osaka Metropolitan University Graduate School of Medicine, 1-4-3 Asahimachi Abenoku, Osaka, 545-8585, Japan.
Background: Fractional flow reserve (FFR) can be estimated by analysis of intravascular imaging in a coronary artery; however, there are no data for estimated FFR in an extremity artery. The aim of this concept-generating study was to determine whether it is possible to estimate the value of peripheral FFR (PFFR) by intravascular ultrasound (IVUS) analysis also in femoropopliteal artery lesions.
Methods: Between April 2022 and February 2023, PFFR was measured before endovascular therapy in 31 stenotic femoropopliteal artery lesions.
Residual power series scheme treatments for fractional Klein-Gordon problem arising in soliton theory.
Sci Rep
December 2024
Department of Mathematics, Faculty of Science, South Valley University, Qena, 83523, Egypt.
The Klein-Gordon problem (KGP) is one of the interesting models that appear in many scientific phenomena. These models are characterized by memory effects, which provide insight into complex phenomena in the fields of physics. In this regard, we propose a new robust algorithm called the confluent Bernoulli approach with residual power series scheme (CBCA-RPSS) to give an approximate solution for the fractional nonlinear KGP.
View Article and Find Full Text PDFComparison of Fluid Flow Rates by Fluid Height and Catheter Size in Normal and Hypertensive Blood-Pressure Scenarios.
Healthcare (Basel)
December 2024
College of Nursing Science, Kyung Hee University, 26, Kyunghee-daero, Dongdaemun-gu, Seoul 02447, Republic of Korea.
Objectives: This study is performed to determine the effects of fluid height, inner catheter diameter, and peripheral venous pressure on room-temperature intravenous fluid administration.
Methods: We employed the Bernoulli equation, with frictional forces considered for volumetric analysis.
Results: The results of this study demonstrate that infusion-set height, catheter size, fluid type, and blood pressure significantly affect flow rates.
Volume-preserving geometric shape optimization of the Dirichlet energy using variational neural networks.
Neural Netw
November 2024
Université de Lorraine, CNRS, Institut Elie Cartan de Lorraine, Inria, BP 7023954506 Vandœuvre-lès-Nancy Cedex, France; Institut Universitaire de France (IUF), France. Electronic address:
In this work, we explore the numerical solution of geometric shape optimization problems using neural network-based approaches. This involves minimizing a numerical criterion that includes solving a partial differential equation with respect to a domain, often under geometric constraints like a constant volume. We successfully develop a proof of concept using a flexible and parallelizable methodology to tackle these problems.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!