Blowing Flow Research Articles

An exact solution based on a three-energy equation model for gaseous transpiration cooling through a bi-disperse porous medium

Abstract A local thermal non-equilibrium analysis was made to assess potential use of bi-disperse porous walls for a transpiration cooling system. A three-energy equation model successfully used for the transient thermal analysis of bi-disperse packed bed thermocline storage systems was introduced to investigate various heat transfer aspects of transpiration cooling through a bi-disperse porous wall made of combination of large and small particles. Three independent energy balance equations, namely, the energy equation of the coolant gas phase, that of the solid phase of large particles and that of small particles are coupled with one another to obtain a set of exact expressions for all three individual temperature distributions across the porous wall for given thermal boundary conditions of the third kind. It has been revealed that the solid wall temperature of the bi-disperse porous wall stays lower than that of the mono-disperse porous wall in the high Peclet number range, resulting in a higher overall cooling efficiency for a given blowing flow rate. Furthermore, the analysis provides a suitable range of the Peclet number, under which the transpiration cooling should be operated to suppress excessive heat loss to the coolant reservoir at the same time to ensure a high overall cooling efficiency.

Dynamics and control of a high-altitude balloon with slung load

Abstract The high-altitude balloon proposed in this paper is a long-life balloon carrying a payload through a cable that flies at 20km altitude in near space. A dynamic model of the system, including the thermodynamics of the buoyancy body coupled with a hanging model of the pod, is developed using the Newton–Euler method. The buoyancy body consists of a helium balloon and a ballonet. A differential pressure difference-based altitude adjustment is achieved by tracking the pressure difference at the target altitude. A dynamic simulation of the buoyancy body with a slung pod in autonomous vertical takeoff and altitude regulation processes is presented. The internal thermodynamic variations and pressure differential of the buoyancy body are given. The air mass exchange and blower flow control of the ballonet are validated. The altitude holding error is analysed. The maximum pull force that the cable can withstand is calculated, and the maximum attitude angles of the pod during the ascending and descending processes are depicted. Simulation results provide basic knowledge for the structural design and payload installation of pods.

In-depth analysis on the mechanism and reaction efficiency of hydrogen deoxidation in ultra-low carbon steel

The reaction mechanism and efficiency of hydrogen deoxidation used in ultra-low carbon steel are explored in this work. A combination of first-principle simulations and thermodynamic calculations were performed on the reaction mechanisms of hydrogen with dissolved oxygen. Laboratory thermal state experiments were used to analyze the effects of different initial oxygen contents of steel and different hydrogen injection flow rates on the deoxidation ability. The results show that the hydrogen deoxidation mainly happens with the gas state of H2 since there are more reactive sites of H atoms in the gas bubble compared to the dissolved H. Higher initial oxygen content and larger hydrogen blowing flow rate are beneficial to the deoxidation reaction efficiency. With hydrogen deoxidation, the inclusion number can be reduced by half compared to Al deoxidation, and the finally total oxygen content can reach 6.8 × 10–6. The actual reaction hydrogen utilization efficiency fluctuates between 0.13 %-1.17 % in this study, which can be improved by extending the resistance time of H2 bubbles in the molten steel. This paper provides in-depth theoretical support and atomic-scale insights into the reaction between hydrogen and oxygen in steel, building a foundation for the hydrogen application in the production of ultra-low-carbon steel.

Measurement and prediction of the detachment of Aspergillus niger spores in turbulent flows

Aspergillus niger (A. niger) spores can induce numerous health problems. Once the airflow-imposed drag force on an A. niger spore exceeds its binding force with the colony, the spore is detached. Turbulent flow may considerably increase the spore detachment. No method is currently available for prediction of the drag force on a spore and its detachment in turbulent flows. This investigation measured the turbulent velocities and detachment of A. niger colonies in a wind tunnel. Computational fluid dynamics (CFD) was employed to model an A. niger unit subjected to turbulent flow blowing. The top 1 % quantile instantaneous velocity of the turbulent flow was specified as the steady entry flow boundary condition for solving the peak velocity distribution and the peak drag forces onto spores. The predicted spore detachment ratios were compared with the measurement data for model validation. The results revealed that the spore detachment ratios with a turbulence intensity of 17 % to 20 % can be twice to triple the ratio with a turbulence intensity of approximately 1 %, when the average velocity for blowing remains the same. The proposed CFD model can accurately predict the detachment ratios of the A. niger spores. Environmental ImplicationSome people are sensitive to the Aspergillus niger (A. niger) spores, and excessive exposure can cause nasal congestion, skin tingling, coughing, and even asthma. Turbulent flow can considerably increase the spore detachment, due to the increased airflow-imposed drag force on the spores during turbulence. This investigation developed a numerical model to solve for the peak velocity distribution and the peak drag forces onto spores in turbulent flows to predict the spore detachment. With the numerical tool, the airborne fungal spore concentrations would be predictable, which paves a way for intelligent and precise control of fungal aerosol pollution.

Effect of Differential Flow Blowing Argon and Nozzle Position on Mixing Time and Slag Eye in Dual Nozzle Ladle Using Water Model Experiment

Effect of Differential Flow Blowing Argon and Nozzle Position on Mixing Time and Slag Eye in Dual Nozzle Ladle Using Water Model Experiment

Simulation of Fluid Flow in the Top–Bottom Combined Blowing Converter

The flow in the top–bottom combined blowing converter has an important impact on processes such as slagging, dephosphorization, decarburization, the heating of molten steel, and the homogenization of steel composition and temperature. A 1/6 reduced scale model based on a 210 t converter was used for the mathematical simulation. The validity of the model was verified by comparing the variation in cavity sizes caused by changes in the lance height and flow rate of the physical model with the numerical results. It was found that, in the bottom blowing converter, the area with higher velocity was distributed in the inverted conical plume. In top blowing, the area with higher velocity was distributed on the surface of a molten bath. The area of higher molten bath velocity in the combined blowing converter further increased. Compared with the top blowing converter, the increased percentage of the area-averaged velocity in the combined blowing converter first increased and then decreased as the distance from the bottom increased. When the top blowing flow rate changed, the combined blowing made the velocity change at the top of a molten bath smaller. The decrease in lance height significantly reduced the ratio of “inactive zone”, while the effect of the change in the flow rate was slight.

Numerical investigation on influences of injection angle of bottom blowing bubbles on multiphase flow characteristics and wall erosion of converter

In this work, a novel bottom blowing approach based on inclined injection bubbles to enhance the multiphase flow mixing is proposed. An Eulerian-Eulerian model, validated via published experimental data, is established to numerically reproduce the stirring process of a bottom blowing converter. The effects of injection angle on the multiphase flow characteristics and wall erosion are then systematically investigated. Firstly, the influence of bottom blowing flow rate (10 m/s, 14 m/s, 20 m/s) on the mixing efficiency is discussed. Then, the effects of injection angle (0°, 5°, 10°, 15°, 20°) on the flow characteristics, mixing efficiency and wall erosion are studied in detail based on the bottom blowing flow rate of 14 m/s. The results show that increasing the bottom blowing flow rate is beneficial to shorten the mixing time. With the increase of the injection angle, the mixing time first decreases and then increases. As a result, the optimal angle for the most efficient mixing is determined as 5° when the flow rate is 14 m/s. When the injection angle is 5°, the air velocity on the axis and the negative tangent line is maximum. But the velocity is minimal on the positive tangent line. The injected air forms bubble plume that promotes the circulation of water. The most serious erosion area of the converter wall is located at the junction of molten steel surface and converter wall, followed by vicinity of the tuyere. However, with the increase of the injection angle, the average wall shear stress fluctuates only slightly. The obtained results are helpful to better understand the mechanism of bubble flow field in gas-liquid two-phase and also to improve the smelting efficiency in iron and steel metallurgy.

Parametric cerebral blood flow and arterial transit time mapping using a 3D convolutional neural network.

To reduce the total scan time of multiple postlabeling delay (multi-PLD) pseudo-continuous arterial spin labeling (pCASL) by developing a hierarchically structured 3D convolutional neural network (H-CNN) that estimates the arterial transit time (ATT) and cerebral blow flow (CBF) maps from the reduced number of PLDs as well as averages. A total of 48 subjects (38 females and 10 males), aged 56-80 years, compromising a training group (n = 45) and a validation group (n = 3) underwent MRI including multi-PLD pCASL. We proposed an H-CNN to estimate the ATT and CBF maps using a reduced number of PLDs and a separately reduced number of averages. The proposed method was compared with a conventional nonlinear model fitting method using the mean absolute error (MAE). The H-CNN provided the MAEs of 32.69 ms for ATT and 3.32 mL/100 g/min for CBF estimations using a full data set that contains six PLDs and six averages in the 3 test subjects. The H-CNN also showed that the smaller number of PLDs can be used to estimate both ATT and CBF without significant discrepancy from the reference (MAEs of 231.45 ms for ATT and 9.80 mL/100 g/min for CBF using three of six PLDs). The proposed machine learning-based ATT and CBF mapping offers substantially reduced scan time of multi-PLD pCASL.

A Comparative Study of the Influences of Leading-Edge Suction and Blowing on the Aerodynamic Performance of a Horizontal-Axis Wind Turbine

The aerodynamic performance of a National Renewable Energy Laboratory Phase VI horizontal-axis wind turbine (HAWT) equipped with blades characterized by leading-edge suction and blowing was analyzed numerically in three dimensions using computational fluid dynamics. The effects of leading-edge suction and blowing flow control methods on the flow field and aerodynamic characteristics of the HAWT and its performance were compared. The results suggest that leading-edge suction is superior to leading-edge blowing in suppressing the flow separation on the suction side of the turbine blade and improving the turbine aerodynamic characteristics. However, compared with the baseline turbine, the bending moment acting on the rotating blade of the HAWT to which suction or blowing is applied increased. This increment was greater for turbines with leading-edge blowing flow control blades. The effects of different arrangements of suction slots on the performance of the HAWT were analyzed. The results showed that the net wind power coefficient of the HAWT after deducting the energy consumption of the suction control was 45% higher than that of conventional turbines, indicating great potential for practical applications.

Методы управления ударно-волновыми структурами во входном сечении высокоскоростного воздухозаборника летательного аппарата

The paper considers features of regulating shock-wave structures using the gas blowing into the flow region from perforated boundaries, as well as by means of energy supply to the compression shocks. Scientists both in our country and abroad are actively studying the porous structures. Calculations in the gas dynamics software packages and using the MATLAB are making it possible to determine the flow blowing effect on rearrangement of the emerging shock-wave structures, which analysis with mathematical apparatus of the shock (detonation) polars allows evaluating their diversity with the pulsed energy supply to the compression shocks. Methods of these structures regulation under study contribute to improving characteristics of the supersonic aircraft and creation of their modernized designs taking into account transformation criteria of the shock-wave structures, which in many cases could be unstable.

Influence of Micro-Blowing Technique Hole Parameters on Drag Reduction of Civil Aircraft Engine Nacelle: A Computational Study

The numerical parametric analysis conducted to analyze the impact of micro-blowing technique (MBT) hole-parameters are quite few at the present stage. The main aim of this research paper is to analyze the effect of micro blowing flow rate and its different hole-parameters on the skin friction drag reduction of an aircraft engine nacelle operating at cruise conditions. The primary tasks are focused to understand the behavior of the flow characteristics at the vicinity of the micro-porous holes by means of different types of MBT configurations. The interaction between main-stream flow and the micro-channel flow is numerically solved by using the Reynolds average Navier-Stokes equation and the k-omega SST is used to model the turbulent flow at the vicinity of the wall region. The hole-pattern is kept aligned in a single-row channel and the shape of the hole cross-section is kept straight to obtain an overall simplicity of the simulation model. The influences of the micro blowing technique are quite clearly seen from the simulation results, as there is a significant reduction in the velocity gradient between the solid engine nacelle surface and all the MBT configurations. The porous engine nacelle surface with zero blowing velocity is capable to reduce the skin friction drag by 7.045 % than of its solid surface, implying that the presence of the micro-porous holes possesses low effective surface roughness, and it is an effective method to manipulate the turbulent boundary layer. The optimum skin friction drag reduction is observed when the geometrical characteristics of the holes possess small diameter and high aspect ratio.

Bibliometric and visual analysis of coronary microvascular dysfunction.

Coronary microvascular dysfunction (CMD) may play an important role in various cardiovascular diseases, including HFpEF and both obstructive and non-obstructive coronary artery disease (CAD). To date, there has been no bibliometric analysis to summarize this field. Here, we aim to conduct a bibliometric analysis of CMD to determine the current status and frontiers in this field. Publications about CMD were taken from the Web of Science Core Collection database (WOSCC). WOSCC's literature analysis wire, the VOSviewer 1.6.16, and CiteSpace 5.1.3 were used to conduct the analysis. A total of 785 publications containing 206 reviews and 579 articles are included in the sample. The leading authors are Iacopo Olivotto, Paolo G. Camici, and Carl J. Pepine. The most productive institutions are the University of Florence, Cedars Sinai Medical Center, and Harvard University. The most productive countries are the USA, Italy, and England. There are a total of 237 journals that contribute to this field, and the leading journals in our study were the International Journal of Cardiology, the European Heart Journal and the JACC. From 2012 to 2021, the top three most-cited articles focused on the association between HFpEF and CMD. The important keywords are heart failure, hypertrophic cardiomyopathy, chest pain, women, coronary flow reserve (CFR), endothelial dysfunction and prognostic value. "Positron emission tomography" shows the strongest burst strength, followed by "blow flow" and "artery." The keywords that started to burst from 2015 are particularly emphasized, including "heart failure," "coronary flow reserve," and "management." Studies about CMD are relatively limited, and the largest contribution comes from the USA, Italy and England. More studies are needed, and publications from other countries should be enhanced. The main research hotspots in the CMD field include CMD in patients with HFpEF, sex differences, the new methods of diagnosis for CMD, and the effective treatment of CMD. Attention should be given to CMD in patients with HFpEF, and untangling the association between CMD and HFpEF could be helpful in the development of physiology-stratified treatment for patients with CMD and HFpEF.

Abstract 196: Association Between Continuous Carotid Blow Flow And Continuous Cerebral Perfusion Indexes Assessment By NIRS In A Porcine Model Of Ventricular Fibrillation During CPR

[Background]: Maintenance of cerebral blood flow during cardiopulmonary resuscitation (CPR) is a critical factor affecting the neurological outcome of patients after cardiac arrest. However, dynamic indicator of cerebral blood flow during CPR is not established. Near infrared spectroscopy (NIRS) is a non-invasive technique capable of detecting changes in cerebral blood volume continuously. The aim of this study is to compare cerebral perfusion during CPR obtained by continuous measure of carotid blow flow (CBF) using flow sensor with continuous cerebral perfusion indices (CPI) assessment by NIRS in a porcine model of ventricular fibrillation (VF) cardiac arrest. [Methods]: CBF during CPR were measured in 21 swine (25± 3 kg) using extra-vascular flow probes positioned around the common carotid arteries. The optodes of the NIRS were attached to the skull bone. Following baseline measurements, VF was electrically induced. After the interval of untreated VF, CPR was continued for 25 min, during which mechanical and manual CPR was alternated at every 5 min intervals. CBF and CPI were measured continuously during CPR. The mean volume of CBF and CPI was calculated average 10 beats in each phase. Correlations between CBF volume and CPI were analyzed by Spearman's rank correlation. [Results]: The followability of CBF and CPI during CPR was good. The Spearman's rank correlation coefficient between CBF volume and CPI was different by sections and it was suggested that the CBF volume was too small to assess the correlation in many sections. If the sections with CBF volume>0.4 ml were extracted and reanalyzed, the rate of sections correlated between CBF volume and CPI were increased (Spearman’s correlation coefficient≧0.4 was 41.3%, Spearman’s correlation coefficient≧0.7 was 17.5%).(Table) [Conclusions]: It was suggested that CPI by NIRS can reflect the CBF during CPR in the sections where enough CBF is.

A comprehensive analysis of flow blowing and its effects on change in main flow conditions and loss generation in compressible flows

In this study, flow blowing into compressible main stream is analyzed using analytical models and Computational Fluid Dynamics (CFD). First, an analytical model based on the general form of equations for flow blowing into compressible main stream is presented. A loss model that provides a complete expression for total entropy generation due to flow blowing process by considering the irreversibilities in both the main stream and the blowing flow is developed next. Equations from the analytical model are solved numerically and the results obtained are used together with the loss model to demonstrate the effect of blowing angle, stagnation conditions of the blowing flow, and local Mach number in front of the blowing location on the change in the conditions of the main stream, choking mass flow rate and loss generation in terms of entropy production. Finally, results from theoretical models are checked against the solution of the Navier-Stokes equations using CFD. For subsonic flows, an excellent agreement between the theoretical results and CFD is found for up to 7% blowing mass flow rate and 90 degree blowing angle, while for supersonic flows the agreement is reasonably well for only up to 5% blowing mass rate and 90 degree blowing angle.

The Positive and Negative Synergistic Airflow-Type Jujube Fruit Harvester (P-N JH)

Low operation efficiency and poor working performance are the main reasons that restrict the application of pneumatic date pickers. In this study, it is proposed to use positive pressure air flow blowing and negative pressure air flow suction to pick jujube fruit and to use inertia air flow to remove impurities and design a positive and negative collaborative air flow type date fruit harvester (P-N JH). The second-order regression model of test factors and response indexes was established by using the central composite design method, and the operating performance of P-N JH was evaluated and comprehensively optimized, and the optimal combination of operating parameters was obtained: positive pressure wind speed, negative pressure wind speed, and travel speed were 16.8 m·s−1, 34.0 m·s−1, and 1.5 m·s−1, respectively. In addition, the verification test results show that the pickup rate, impurity rate, damage rate, and operating efficiency are 97.21%, 2.15%, 1.08%, and 2170 kg/h, respectively. The operating performance of P-N JH not only meets the requirements of jujube picking but also significantly improves the operating efficiency compared with the traditional air-suction jujube harvester. This study can provide theoretical and technical reference for the harvesting of air-suctioned dates; it also provides a new way of thinking for jujube fruit picking.

Research on Mixing Behavior in a Combined Top–Bottom–Side Blown Iron Bath Gasifier

The iron bath gasifier studied in this paper is a new type of reactor for handling organic solid waste, in which the complex transport phenomena comprising high temperature, the multiphase flow, mixing, and chemical reaction takes place. It is of great significance to study the melt’s flow and mass transfer behavior in this reactor. The influence of different process parameters on the mixing behavior of the molten pool was studied by the water modeling experiment and numerical simulation method. The experimental results show that the height of the water phase has a highly significant effect on the mixing time of the molten pool, followed by the horizontal angle of the side gun and the bottom blowing flow rate. As the height of the water increases, the mixing time decreases. When the horizontal angle of side lances increases, the mixing time decreases. With the increase in the flow rate of the bottom lance, the mixing time decreases. The results obtained by numerical simulation were compared with the experimental results to determine the reliability of the mathematical model for future optimization of the process parameters by numerical simulation. These studies are helpful for optimizing the design of the reactor and improving the process parameters.

Wake stabilization behind a cylinder by secondary flow over the leeward surface

Porous coating and blowing jets are both effective flow control methods for a bluff body. In the present study, we conducted wind tunnel experiments to investigate the combined control effects on a circular cylinder. The flow control was achieved by active steady blowing flows through the structured porous surface on the leeward side of the cylinder. The Reynolds number Re in the experiments, based on the cylinder outer diameter, was 1.0×104. The control effects were evaluated by a non-dimensional blowing momentum coefficient Cμ, which was determined by various blowing mass flow rates, incoming wind speed, and the geometry of the porous surface. Reduced-order models, including proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), were employed to analyze the wake stabilization effects of the secondary jet flows. We found that, under the control of secondary flows ejected from the porous region of the cylinder, POD modal characteristics in the global flow wake were changed; temporal and spatial properties of DMD transformed; frequency and mode of the vortex shedding process shifted; statistical turbulent flow characteristics ameliorated; and the estimated drag coefficients restrained. Experimental results in the present study demonstrated that the secondary flow ejected from the structured porous surface and the resultant small-scale vortices could stabilize the cylinder wake with proper Cμ values.

A numerical evaluation of a novel recovery fresh air heat pump concept for a generic electric bus.

Since the outbreak of the worldwide COVID-19 pandemic, public transportation networks have faced unprecedented challenges and have looked for practical solutions to address the rising safety concerns. It is deemed that in confined spaces, operating heating units (and cooling) in non-re-circulation mode (i. e., all-fresh air mode) could reduce the airborne transmission of this infectious disease, by reducing the density of the pathogen and exposure time. However, this will expectedly increase the energy demand and reduce the driving range of electric buses. To tackle both the airborne transmission and energy efficiency issues, in this paper a novel recovery heat pump concept, operating in all-fresh air mode, was proposed. The novelty of this concept lies in its potential to be applied to already manufactured/in-service heat pump units as it does not require any additional components or need for redesigning the heating systems. In this concept, the cabin exhaust air is directed to pass through the evaporator of the heat pump system to recover part of the waste heat from the cabin and to improve the efficiency of the system. In this paper, a 0D/1D coupled model of a generic single-deck cabin and a heat pump system was developed in the Simulink environment of MATLAB (R2020b) software. The model was run in two different modes, namely the all-fresh air (as a baseline and a recovery heat pump concepts), and the air re-circulation mode (as a conventional heat pump concept with a 50% re-circulation ratio). The performance of these concepts was investigated to evaluate how an all-fresh air policy could affect the performance of the system, as well as the energy-saving potential of the proposed recovery concept. The performance of the system was studied under different ambient temperatures of −5 °C, 0 °C, and 5 °C, and for low and moderate occupancy levels. Results show that implementing the all-fresh air policy in the recovery and baseline concepts significantly improved the ventilation rate per person by at least 102% and at most 125%, compared to the air-re-circulating heat pump. Moreover, adopting the recovery concept reduced the power demand by at least 8% and at most 11%, compared to the baseline all-fresh air heat pump, for the selected fan and blower flow rates. The presented results in this paper along with the applicability of this concept to in-service mobile heat pumps could make it a feasible, practical, and quick trade-off solution to help the bus operators to protect people and improve the energy efficiency of their service.

TRPV1 in arteries enables a rapid myogenic tone.

Arterioles maintain blow flow by adjusting their diameter in response to changes in local blood pressure. In this process called the myogenic response, a vascular smooth muscle mechanosensor controls tone predominantly through altering the membrane potential. In general, myogenic responses occur slowly (minutes). In the heart and skeletal muscle, however, tone is activated rapidly (tens of seconds) and terminated by brief (100 ms) arterial constrictions. Previously, we identified extensive expression of TRPV1 in the smooth muscle of arterioles supplying skeletal muscle, heart and fat. Here we reveal a critical role for TRPV1 in the rapid myogenic tone of these tissues. TRPV1 antagonists dilated skeletal muscle arterioles in vitro and in vivo, increased coronary flow in isolated hearts, and transiently decreased blood pressure. All of these pharmacologic effects were abolished by genetic disruption of TRPV1. Stretch of isolated vascular smooth muscle cells or raised intravascular pressure in arteries triggered Ca2+ signalling and vasoconstriction. The majority of these stretch-responses were TRPV1-mediated, with the remaining tone being inhibited by the TRPM4 antagonist, 9-phenantrol. Notably, tone developed more quickly in arteries from wild-type compared with TRPV1-null mice. Furthermore, the immediate vasodilation following brief constriction of arterioles depended on TRPV1, consistent with a rapid deactivation of TRPV1. Pharmacologic experiments revealed that membrane stretch activates phospholipase C/protein kinase C signalling combined with heat to activate TRPV1, and in turn, L-type Ca2+ channels. These results suggest a critical role, for TRPV1 in the dynamic regulation of myogenic tone and blood flow in the heart and skeletal muscle. KEY POINTS: We explored the physiological role of TRPV1 in vascular smooth muscle. TRPV1 antagonists dilated skeletal muscle arterioles both ex vivo and in vivo, increased coronary perfusion and decreased systemic blood pressure. Stretch of arteriolar myocytes and increases in intraluminal pressure in arteries triggered rapid Ca2+ signalling and vasoconstriction respectively. Pharmacologic and/or genetic disruption of TRPV1 significantly inhibited the magnitude and rate of these responses. Furthermore, disrupting TRPV1 blunted the rapid vasodilation evoked by arterial constriction. Pharmacological experiments identified key roles for phospholipase C and protein kinase C, combined with temperature, in TRPV1-dependent arterial tone. These results show that TRPV1 in arteriolar myocytes dynamically regulates myogenic tone and blood flow in the heart and skeletal muscle.

Modeling the effect of cerebral capillary blood flow on neuronal firing

Adequate cerebral blood flow has long been recognized as essential for the maintenance of the neuronal function while interruption of cerebral blood flow for durations as short as minutes can result in permanent brain damage. A primary goal of this work is to determine how a neuron’s ability to respond to synaptic input depends on parameters that control cerebral blood flow. A complex mathematical model is constructed that integrates detailed biophysical models of neuronal action potentials, mitochondrial ATP production and cerebral capillary blood flow. The model also provides insights of the role of astrocytes in maintaining neuronal responses, as well as the impact of elevated cytosolic calcium, due to increased synaptic activity, on mitochondrial ATP production. Both dynamical systems analysis and numerical simulations are used to determine how the maximum frequency at which the neurons can respond to synaptic input depends on capillary blow flow, as well as the ability of astrocytes to buffer extracellular potassium and cytosolic calcium handling. Results are presented for both the cases of homogenous and heterogeneous capillary networks. These results demonstrate, through this interconnected model, that heterogeneity of the capillary flow results in a decrease in the ability of neurons to respond to synaptic stimulation and that intact glial function provides a further protective role for the neurons.