Fluid Motion Research Articles

Dynamics of Fluids in the Cavity of a Rotating Body: A Review of Analytical Solutions

Since the middle of the 20th century, an understanding of the diversity of the natural magnetohydrodynamic phenomena surrounding us has begun to emerge. Magnetohydrodynamic nature manifests itself in such seemingly heterogeneous processes as the flow of water in the world’s oceans, the movements of Earth’s liquid core, the dynamics of the solar magnetosphere and galactic electromagnetic fields. Their close relationship and multifaceted influence on human life are becoming more and more clearly revealed. The study of these phenomena requires the development of theory both fundamental and analytical, unifying a wide range of phenomena, and specialized areas that describe specific processes. The theory of translational fluid motion is well developed, but for most natural phenomena, this condition leads to a rather limited model. The fluid motion in the cavity of a rotating body such that the Coriolis forces are significant has been studied much less. A distinctive feature of the problems under consideration is their significant nonlinearity, (i.e., the absence of a linear approximation that allows one to obtain nontrivial useful results). From this point of view, the studies presented here were selected. This review presents studies on the movements of ideal and viscous fluids without taking into account electromagnetic phenomena (non-conducting, non-magnetic fluid) and while taking them into account (conducting fluid). Much attention is payed to the macroscopic movements of sea water (conducting liquid) located in Earth’s magnetic field, which spawns electric currents and, as a result, an induced magnetic field. Exploring the processes of generating magnetic fields in the moving turbulent flows of conducting fluid in the frame of dynamic systems with distributed parameters allows better understanding of the origin of cosmic magnetic fields (those of planets, stars, and galaxies). Various approaches are presented for rotational and librational movements. In particular, an analytical solution of three-dimensional unsteady magnetohydrodynamic equations for problems in a plane-parallel configuration is presented.

Implosion mechanisms of underwater ring-stiffened metallic cylindrical shells

Underwater cylindrical shells are prone to implosion due to the surrounding high hydrostatic pressure, and introducing ring-rib is a promising approach to reduce the risk. However, the influences of the ring-rib on the deformation mode and the fluid-structure interaction mechanism are still unclear. This paper investigates the dynamic response of ring-stiffened cylindrical shells during the implosion process. The finite element model is firstly established and the numerical simulation is verified by the existing experiment. Then, the numerical method is used to simulate the implosion of ring-stiffened cylindrical shells with various geometrical parameters. The fluid motion, induced pressure and deformation features are investigated and the relationship between them is clarified. Finally, pure and ring-stiffened cylindrical shell implosions are compared and parametric analyses are performed by varying the number and thickness of ring-ribs. Results show that ring-stiffened cylindrical shells with higher collapse resistance deform asymmetrically and the flow field response changes depending on the deformation mode. Introduction of ring-ribs can significantly increase the critical pressure and reduce the percentage of induced pressure. As the number and thickness of ribs increased, the critical and peak implosion pressures of the ring-stiffened cylindrical shells increased by 153% and 146%, respectively.

Numerical simulation analysis of stable flow of hydrate slurry in gas-liquid-solid multiphase flow

The study of multiphase flow characteristics of hydrate slurry was crucial for controlling the risks associated with hydrate slurry transport in deep-water oil and gas operations. Currently, multiphase flow research on the hydrate slurry flow system focuses on two-phase (solid-liquid) flow studies in single short straight pipes or elbows. This paper established a geometric model based on an experimental loop of high-pressure natural gas hydrate slurry. The Euler model contained n momentum equations and continuity equations for each term, and the Euler model can couple the pressure term with the surface exchange coefficients. Therefore, Euler model was suitable to deal with complex fluid motion problems. Such as bubble flow problem, floating problem, particle suspension problem and fluidized bed problem. In this paper, the hydrate particles in the grout were set as regular round spheres and do not decompose, so the Euler model was suitable for the simulation of the gas-liquid-solid three-phase flow of hydrate grout in the loop. The Euler model was used to simulate the three-phase (gas-liquid-solid) expansion in the loop, focusing on the influence of hydrate slurry inlet flow rate, inlet hydrate volume fraction, liquid phase viscosity and pipe diameter on slurry flow characteristics. The results are as follows:1) Based on orthogonal experiments, pipe diameter has the most significant impact on the pressure drop of the entire pipe section, while liquid phase viscosity has the greatest impact on the average aggregation particle diameter of hydrate on the cross section.2) The distribution of hydrate phase is related to the direction of the loop. Under the influence of gravity, hydrates are primarily dispersed in the liquid phase, with a high concentration in the solid-liquid mixing zone, tend towards the gas phase zone. Hydrate particles are symmetrically distributed in the vertical cross-section, with smaller particle diameters in the solid-liquid mixing zone compared to the gas phase and liquid phase zone 3). In the elbow section, centrifugal force and density difference cause hydrate particles to aggregate towards the lower pipe wall on the outside of the elbow. This results in the disappearance of the liquid phase zone, higher hydrate concentration on the outside of the elbow, and smaller hydrate particle diameter in the solid-liquid mixing zone compared to the gas phase zone.4). Throughout entire loop, the viscosity of the slurry in the solid-liquid mixing zone was the highest, and the volume fraction of hydrate particles was symmetrical both vertically and horizontally. To validate the simulation results, high-pressure multiphase flow hydrate generation experiments were conducted in a 6 MPa hydrate slurry experimental loop. The stable flow pressure drop value of the slurry was compared to the simulation results. The relative error between the simulated and experimental pressure drops is less than 15%, falling within an acceptable range and matching the experimental results. This proved that the multiphase simulation technique of hydrate slurry gas-liquid-solid in the loop can effectively guide the safe transportation of hydrate slurry under actual working conditions.

Fluid-reduced-solid interaction (FrSI): Physics- and projection-based model reduction for cardiovascular applications

Fluid-solid interaction (FSI) phenomena play an important role in many biomedical engineering applications. While FSI techniques and models have enabled detailed computational simulations of flow and tissue motion, the application of FSI can present challenges, particularly when data for constraining models is sparse and/or when fast computational simulations are required for assessment. In this paper, we propose a novel method for flexible-wall fluid dynamics in an ALE framework applicable for cardiovascular applications where adaptive fluid motion that emulates patient data is required. Efficiency and model simplicity are gained by a physics-based reduction to solid membrane formulations at the fluid-tissue interface combined with a Galerkin projection to a subspace spanned by boundary motion modes, leveraging snapshots observed from imaging data by use of Proper Orthogonal Decomposition (POD). The resulting fluid-reduced-solid interaction (FrSI) model is verified for a series of examples, illustrating efficacy and efficiency. Focusing on an idealized left ventricle model, we demonstrate homogenization of transmural active stress along with the capacity to accommodate prestress in the FrSI model, accounting for whole cycle mechanics by coupling to 0D pre- and afterload models (showing end-diastolic and end-systolic projected endocardial surface position errors of less than 1.5% and 3.5%, respectively). Further, we present strategies to compensate for the inherent approximation errors of the FrSI model, allowing for minimizing both the integral and spatial error between reduced and full-order model by re-calibrating parameters that govern diastolic and systolic function. Finally, the ability of FrSI to extrapolate to impaired system states (increased afterload, localized region of infarct) is shown, providing a simple yet effective strategy to enhance the POD subspace to further reduce errors. These results illustrate the potential of FrSI to streamline the simulation of hemodynamics in the heart and cardiovascular system.

Random processes in modeling durability of building and structure

The problem of buildings and structures durability during their long-term operation in aggressive environments is discussed. It is closely connected with the problem of destruction of composite materials as a random process of birth, development, and death of defects at chemical corrosion. The content of the study is to analyze the influence of non-stationary chemical reactions occurring in real conditions on these processes. The analysis is carried out taking into account the incidental physical phenomena affecting corrosion, the most important of which is the diffusion of initial substances and reaction products occurring under different hydrodynamic conditions, i.e., the nature of fluid motion and its pressure which stimulates corrosion. The synthesis of three processes – chemical kinetics, diffusion, and hydrodynamics – allows us to study one of the possible scenarios of corrosion process development as a Markov process based on the statistical theory of the “weakest” link and the joint distribution of the random material and geometric parameters. Numerical analysis of changes in elastic and electrical properties of composite materials under these conditions allows us to substantiate the technology of non-destructive control of changes in the state of the structure. The research results are based on mathematical and statistical modeling.

Advanced numerical simulation techniques in MHD fluid flow analysis using distributed fractional order derivatives and Cattaneo heat flux model

AbstractThis study investigates the flow and heat transfer characteristics of a second‐grade fluid over a flat surface with variable heat flux. Utilizing a mathematical model based on distributed order fractional derivatives, we offer a more precise representation of non‐Newtonian fluid behavior. The associated highly nonlinear equations are tackled numerically through an innovative amalgamation of the finite difference scheme and the technique. Our investigation thoroughly evaluates the influence of several critical parameters on the fluid's motion and thermal characteristics. Notably, the magnetic parameter significantly inhibits the fluid's velocity, illustrating the impact of magnetic forces. Additionally, the power law parameter leads to a decrease in both velocity and temperature profiles, highlighting its influence on fluid dynamics. Furthermore, changes in the Reynold number and the second‐grade fluid parameter are observed to cause a substantial increase in skin friction, by approximately 40% to 50%. These simulation results provide valuable insights into the complex interaction between fluid flow and heat transfer characteristics, enhancing our understanding of such systems in industrial applications.

NUMERICAL ANALYSIS IN ARTERIAL STENOSIS AFFECTED BY ISCHEMIC HEART DISEASE USING FINITE VOLUME METHOD

Atherosclerosis is the narrowing of blood vessels caused by the buildup of cholesterol plaque on the walls of the arteries. Excessive buildup of cholesterol plaque disrupts the circulatory system, thereby affecting the speed and pressure of blood flow. In the long term, atherosclerosis can cause ischemic heart disease. This study aims to analyze the influence of stenosis, initial velocity, and diameter on the velocity and pressure of blood flow in narrowed arteries that cause ischemic heart disease. In this research, a Navier Stoke mathematical equation model was built which was solved using the finite volume method with SIMPLE discretization (Semi Implicit Method for Pressure Linked Equations). Finite volume methods are used to analyze unstructured objects such as blood flow. SIMPLE discretization is implemented simply in two and three dimensions with a system of equations containing fluid motion. Matlab and Fluent are software used for process simulations, Matlab for visualizing graphs of numerical calculation results, and Fluent for visualizing blood flow. Based on the simulation results, it can be concluded that the smaller the diameter, the greater the stenosis, and the greater the initial velocity, the greater the blood flow velocity. On the contrary, the diameter gets smaller, the stenosis gets bigger, and the initial velocity gets bigger so that the pressure on the blood flow gets smaller. Blood flow simulation has the potential to contain ischemic heart disease if the maximum speed produced is greater than the maximum normal blood speed, namely 0.45 m/s.

Wave scattering and radiation by a surface-piercing vertical truncated metamaterial cylinder

In this paper, we study wave scattering and radiation by a surface-piercing vertical truncated metamaterial cylinder composed of a closely spaced array of thin vertical barriers, between which fluid can flow. A theoretical model is developed under full depth-dependent linearised water wave theory, where an effective medium equation and effective boundary conditions are employed, respectively, to describe the fluid motion inside the cylinder and match the flow between the fluid regions in and outside the metamaterial cylinder. A damping mechanism is introduced at the surface of the fluid occupied by the metamaterial cylinder to consider the wave power dissipation in narrow gaps between the thin vertical plates. The wave excitation forces acting on the cylinder and the hydrodynamic coefficients can be calculated straightforwardly in terms of the velocity potential inside the cylinder. An alternative way is by using the velocity potential outside the cylinder, the expression of which has the reduction of the integral and an infinite accumulation that are included in the straightforward expression. The results highlight the patterns of the radiated waves induced by the oscillation of the cylinder and the characteristics of the hydrodynamic coefficients. The metamaterial cylinder when fixed in place and with a damping mechanism included is found to capture more wave power than that of a traditional axisymmetric heaving wave energy converter over a wide range of wave frequencies.

Parametric Roll Motion Reduction of a Ship with a Passive Anti-Roll Tank

In this study, the influence of a U-tube passive anti-roll tank on parametric roll motion has been investigated as a mechanical absorber of a dynamic system. Specifically, this paper concentrates on how the initial conditions of a coupled roll motion and fluid motion in the tank act on the performance of an anti-roll tank. Parametrically excited roll motion was modeled as a single degree of freedom system incorporating heave and pitch effects by means of a time-varying restoring moment. Fluid motion in the tank was modeled as a single degree of freedom system. Coupled equations of motion were solved numerically and the results were presented in the time domain. Furthermore, the results were comparatively depicted as maximum roll amplitudes vs. initial values for a ship with and without an anti-roll U-tube tank.

Spontaneous Stochasticity Amplifies Even Thermal Noise to the Largest Scales of Turbulence in a Few Eddy Turnover Times.

How predictable are turbulent flows? Here, we use theoretical estimates and shell model simulations to argue that Eulerian spontaneous stochasticity, a manifestation of the nonuniqueness of the solutions to the Euler equation that is conjectured to occur in Navier-Stokes turbulence at high Reynolds numbers, leads to universal statistics at finite times, not just at infinite time as for standard chaos. These universal statistics are predictable, even though individual flow realizations are not. Any small-scale noise vanishing slowly enough with increasing Reynolds number can trigger spontaneous stochasticity, and here we show that thermal noise alone, in the absence of any larger disturbances, would suffice. If confirmed for Navier-Stokes turbulence, our findings would imply that intrinsic stochasticity of turbulent fluid motions at all scales can be triggered even by unavoidable molecular noise, with implications for modeling in engineering, climate, astrophysics, and cosmology.

The wave resonances and time-dependent wave motion in stratified fluid with permeable bottom

The wave resonances and time-dependent wave motion in stratified fluid with permeable bottom

A Strange Result Regarding Some MHD Motions of Generalized Burgers’ Fluids with a Differential Expression of Shear Stress on the Boundary

In this work, we investigate isothermal MHD motions of a large class of rate type fluids through a porous medium between two infinite horizontal parallel plates when a differential expression of the non-trivial shear stress is prescribed on the boundary. Exact expressions are provided for the dimensionless steady state velocities, shear stresses and Darcy’s resistances. Obtained solutions can be used to find the necessary time to touch the steady state or to bring to light certain characteristics of the fluid motion. Graphical representations showed the fluid moves slower in presence of a magnetic field or porous medium. In addition, contrary to our expectations, the volume flux across a plane orthogonal to the velocity vector per unit width of this plane is zero. Finally, based on a simple remark regarding the governing equations of velocity and shear stress for MHD motions of incompressible generalized Burgers’ fluids between infinite parallel plates, provided were the first exact solutions for MHD motions of these fluids when the two plates apply oscillatory or constant shear stresses to the fluid. This important remark offers the possibility to solve any isothermal MHD motion of these fluids between infinite parallel plates or over an infinite plate when the non-trivial shear stress is prescribed on the boundary. As an application, steady state solutions for MHD motions of same fluids have been developed when a differential expression of the fluid velocity is prescribed on the boundary.

Effects of topographical disturbances on flexural wave motion in a viscous fluid

Main causes of ground disturbances are geological events such as earthquakes, underwater gravity mass flows, volcanic eruptions, and bottom explosions. This paper investigates the effects of transitory ground disturbance on the generation of flexural waves in the presence of a thin floating elastic plate. The problem is formulated using the Stokes stream function and wave potential boundary value problems in a viscous fluid. The expression of the plate deflection is obtained as multiple infinite integrals using the Fourier and Laplace transforms, which is further solved by the steepest descent method. Three types of ground disturbances such as H0(x)=e(−x2/2), H0(x)=e−|x|, and H0(x)=δ(x) are considered. The deflection of the floating elastic plate is investigated in connection to ground disturbances, fluid viscosity, and structural parameters such as mass per unit length of the plate and flexural rigidity. The study reveals that with higher viscosity and flexural rigidity, the amplitude of the plate deflection is reduced. Moreover, these two parameters play a great role in the reduction of plate deflection.

Breather and soliton solutions of a generalized (3 + 1)-dimensional Yu–Toda–Sasa–Fukuyama equation

Fluid mechanics is a branch of physics that focuses on the study of the behavior and laws of motion of fluids, including gases, liquids, and plasmas. The Yu–Toda–Sasa–Fukuyama equation, a class of Kadomtsev–Petviashvili type equations, is a significant integrable model with applications in fluids and other fields. In this paper, we study breather and soliton solutions of a generalized (3 + 1)-dimensional YTSF equation. By utilizing the Hirota bilinear method and Painlevé analysis, we construct solutions in the form of trigonometric and hyperbolic functions and analyze the interaction between waves graphically. We consider the characteristics of wave distribution along characteristic lines to obtain the distance between each wave and the angle generated, which is beneficial for understanding the ocean wave superposition effect. Additionally, we examine the dynamic characteristics of the wave, such as amplitude, velocity, period, shape, position, width, and phase. Furthermore, we investigate the effects of the system parameters on solitons and breathers.

Analysis of thermal density and heat sink on dissipative nanofluid along magnetized sheet and applications in microelectronic cooling systems

The objective of present analysis is to control excessive thermal behavior in microelectronic devices using heat sink and magnetic field. Improving technological innovation demands proper temperature evacuation in microelectronic components. A feasible method for cooling microelectronics is to use nanofluid, a novel heat-transport liquid. To achieve significant cooling, microelectronic devices must be small with specific operating liquids than regular liquids. The present work investigates the fluid motion and heat transmission properties of nanofluids as advanced cooling fluids for microelectronic coolant systems. A numerical technique is used to investigate the cooling mechanism using stretching surface. Computational fluid dynamics and 2D liquid movement simulation are employed to determine the mathematical model. The governing model is transformed with Keller box method and Newton Raphson technique through MATLAB program. The base liquid is water using laminar motion. The influence of nanoparticles volume fraction, heat sink, variable density and viscous dissipation in the base liquid on heat transmission efficiency of coolant devices is investigated. It is noticed that the fluid temperature decreases as heat sink increases. It is found that the excessive heat is reduced by using magnetic layer and heat sink. The present numerical mechanism is significant for the cooling of microelectronic devices.

Biophysical Mechanisms of Microfluidic Devices: Future in Diagnostics and Microcellular Analyses

Microfluidic dеvicеs (MFDs) havе rеvolutionizеd fluid manipulation and analysis at thе microscalе. They sustain prеcisе control ovеr fluid flow through intricatе nеtworks of microchannеls that allow for the integration of multiplе laboratory practicеs onto a singlе chip, transforming sciеntific rеsеarch and practical applications in biology, chеmistry, and mеdical diagnostics. MFDs havе fundamеntal charactеristics that contributе to thеir functionality and vеrsatility, such as matеrials likе Polydimеthylsiloxanе (PDMS), providing composition flеxibility, cost-effectiveness, and biocompatibility. In MFDs, fluid motion rеgulation involvеs еmploying various flows, microvalvеs, and capillary forcеs, stimulating fluid transport without external еnеrgy. Thе narrow width of the microchannels is advantageous in biomedical applications, as it assures efficient fluid separation and reduced sample volumеs. This tеchnology has еxhibitеd practicality in protеin charactеrization, DNA analysis, cеll sеparation, and hormonal signal rеcognition, еnabling sеnsitivе dеtеction and quantification of biomolеculеs. This provides researchers with valuablе insight into complеx biological procеssеs and disease mechanisms. MFDs play a crucial rolе in simulating complеx biological procеssеs on a small scalе, leading to the emergence of organ-on-a-chip and lab-on-a-chip tеchnologiеs. MFDs hold rеmarkablе promisе in rеvolutionizing cancеr diagnostics, sеrving as еffеctivе platforms for isolating and analyzing cancеr-spеcific biomarkеrs, facilitating еarly dеtеction, pеrsonalizing mеdicinе, and monitoring tumor dynamics in real time. MFDs allow for thе evaluation of therapeutic efficacy and investigation into cancеr metastasis, еnhancing intraopеrativе pathological еvaluation. By lеvеraging thеir uniquе charactеristics, MFDs havе thе potеntial to drivе significant advancеmеnts in cancеr diagnostics and improvе our insight into complеx biological procеssеs, leading to enhanced and personalized therapeutics.

Electro-osmotic flow in nanoconfinement: Solid-state and protein nanopores.

Electro-osmotic flow (EOF) is a phenomenon where fluid motion occurs in porous materials or micro/nano-channels when an external electric field is applied. In the particular example of single-molecule electrophoresis using single nanopores, the role of EOF on the translocation velocity of the analyte molecule through the nanopore is not fully understood. The complexity arises from a combination of effects from hydrodynamics in restricted environments, electrostatics emanating from charge decorations and geometry of the pores. We address this fundamental issue using the Poisson-Nernst-Planck and Navier-Stokes (PNP-NS) equations for cylindrical solid-state nanopores and three representative protein nanopores (α-hemolysin, MspA, and CsgG). We present the velocity profiles inside the nanopores as a function of charge decoration and geometry of the pore and applied electric field. We report several unexpected results: (a) The apparent charges of the protein nanopores are different from their net charge and the surface charge of the whole protein geometry, and the net charge of inner surface is consistent with the apparent charge. (b) The fluid velocity depends non-monotonically on voltage. The three protein nanopores exhibit unique EOF and velocity-voltage relations, which cannot be simply deduced from their net charge. Furthermore, effective point mutations can significantly change both the direction and the magnitude of EOF. The present computational analysis offers an opportunity to further understand the origins of the speed of transport of charged macromolecules in restricted space and to design desirable nanopores for tuning the speed of macromolecules through nanopores.

Significance of heat generation in MHD channel flow of a maxwell fluid with heat suction and blowing effects

This investigation aims to provide numerical analyses for a complex problem involving magnetohydrodynamics (MHD), radiation and heat generation of a Maxwell fluid within a porous medium on the channel. The governing equations for momentum, concentration, and energy are converted from nonlinear partial differential equations (NLPDEs) into nonlinear ordinary differential equations (NLODEs) for concentrated analysis using a similarity transformation. Dimensionless velocity, temperature and concentration fields corresponding to steady motions of Maxwell fluid over a channel are numerically recognized using the bvp4c scheme in MATLAB. We verified our findings by comparing them with existing work, achieving an outstanding agreement. The impact of physical parameters on fluid motion is plotted and debated. The results indicate that as the Deborah number increases, the temperature profile decreases, but the velocity and concentration contours increase for the suction effect. However, the opposite trend is detected for the injection parameter. Heat generation amplifies the temperature contour for suction and injection effects.

A comprehensive multiphysics approach to model solutal buoyancy, thermal convection, and electro-vortex flow phenomena for liquid metal batteries

To alleviate the effects of pollution and global warming, the transition to renewable energy sources is taking place at an accelerating rate. The intermittent nature of renewable energy production can be addressed by an energy storage solution that is low-cost, efficient, and based on earth-abundant materials, and a liquid metal battery (LMB) is coming up as one such solution. Liquid metal battery (LMB) performance, especially its discharge voltage, depends on the concentration profile of cathode which in turn is influenced by fluid flow. In this study, we examine three significant phenomena that impact fluid behavior: solutal buoyancy, internally heated convection, and electro-vortex flow (EVF). Though several attempts have been made to model these processes individually or in a combination of two, a model that simulates all three aspects for resultant fluid flow has not been reported. Therefore, this study develops a comprehensive multiphysics model to simulate the positive electrode that is validated with experimental results for Li||Bi cell operating at 450 °C by coupling all of the aforementioned phenomena. While charging with a current density of 1 A/cm2, our model predicts an average velocity of ∼6 mm/s in the cathode solely due to solutal buoyancy. In the case of discharging, both solutal and internal thermal effects lead to an increase in overpotential to as high as ∼200 mV. Moreover, during discharging, the EVF induced a poloidal fluid flow with a maximum velocity of ∼3–5.5 mm/s at 1 A/cm2, reducing mass transport overpotential by ∼10 mV, but it could not disrupt the lighter intermetallic stratification layer on top of the cathode. Additionally, we investigated the charging overpotential phenomenon due to unstable stratification. This all-inclusive model leveraging solutal, thermal, and EVF effects not only offers insights into the fluid motion, concentration gradient, and voltage profile for a lab-scale LMB but can accurately simulate te conditions prevalent in commercial large LMBs, thereby catalysing the path to commercialization of LMBs.

CO2 as an engine for neurofluid flow: Exploring the coupling between vascular reactivity, brain clearance, and changes in tissue properties.

The brain relies on an effective clearance mechanism to remove metabolic waste products for the maintenance of homeostasis. Recent studies have focused on elucidating the forces that drive the motion of cerebrospinal fluid (CSF), responsible for removal of these waste products. We demonstrate that vascular responses evoked using controlled manipulations of partial pressure of carbon dioxide (PaCO2) levels, serve as an endogenous driver of CSF clearance from the brain. To demonstrate this, we retrospectively surveyed our database, which consists of brain metastases patients from whom blood oxygen level-dependent (BOLD) images were acquired during targeted hypercapnic and hyperoxic respiratory challenges. We observed a correlation between CSF inflow signal around the fourth ventricle and CO2-induced changes in cerebral blood volume. By contrast, no inflow signal was observed in response to the nonvasoactive hyperoxic stimulus, validating our measurements. Moreover, our results establish a link between the rate of the hemodynamic response (to elevated PaCO2) and peritumoral edema load, which we suspect may affect CSF flow, consequently having implications for brain clearance. Our expanded perspective on the factors involved in neurofluid flow underscores the importance of considering both cerebrovascular responses, as well as the brain mechanical properties, when evaluating CSF dynamics in the context of disease processes.