Acoustic muffler for high volume fluid flow utilizing Helmholtz resonators with low flow resistance path

1994 ◽  
Vol 96 (1) ◽  
pp. 618-618
Author(s):  
Thomas R. Norris
Keyword(s):  
Fluid Flow ◽  
Flow Resistance ◽  
High Volume ◽  
Low Flow ◽  
Helmholtz Resonators

Quantitative Experimental Investigation on the Flow Characteristics of Nanofluids in Turbulent Flow

2019 ◽  
Author(s):  
Jizu Lv ◽  
Zhenxian Zhang ◽  
Chengzhi Hu ◽  
Minli Bai
Keyword(s):  
Fluid Flow ◽  
Energy Loss ◽  
Turbulent Flow ◽  
Flow Condition ◽  
Flow Resistance ◽  
Flow Characteristics ◽  
Nano Particles ◽  
Low Flow ◽  
Strengthening Effect ◽  
Flow Through

Abstract In addition to the increase of thermal conductivity, heat transferring for nanofluids strengthening mechanism also includes the changes of the flow characteristics, therefore it is needed to take an in-depth research on nanofluids flow characteristics. However previous visualization experiment do not quantitatively analyze the change of flow characteristics after nano-particles is added, do not reveal the mechanism of nanofluids changing the characteristics of the fluid in intense turbulent flow condition. Therefore in this paper, by means of particle image velocimetry, quantitatively study SiO2-water nanofluids flow characteristics in intense turbulent flow condition and analyze the influence of SiO2-water nanofluids on turbulent flow energy by measuring the pressure drop caused by fluid flowing through the channel. Fluid flow through rectangular convex channel (channel composed of continuous staggered rectangular convex platform) to obtain the steady intense turbulent flow. The rectangular convex channel makes the fluid flow through obstacles for several times, so that the flow direction changes for several times, and vortexes are generated in the local scope, which makes turbulence enhance and increases minor loss. In this way, flow can be in the intense turbulent state under a low flow rate, which meets the experiment requirement and is convenient to compare the influence of nano-particles on flow resistance and energy loss. The experiment takes the quantitative PIV experimental research on pure water and the volume fraction of 0.5% SiO2-water nanofluids respectively in the Reynolds number is 2300, 2500, 3000, 4000. Through the experiment, we can obtain nanofluids turbulent flow condition fluctuating velocity, turbulence kinetic, energy loss and so on, and the fluid flow velocity vector, streamline and vorticity graph. Through the quantitative comparison of the spiral numbers, the vorticity distribution, and energy loss, analyze strengthening effect and influence of flow resistance on basic fluid after adding nanoparticles.

Fluid Flow Resistance Through Hemispherical Dimpled Plates in Parallel and Zigzag Configurations

2018 ◽  
Vol 12 (11) ◽  
pp. 885
Author(s):  
Nasaruddin Salam ◽  
Rustan Tarakka ◽  
Jalaluddin Jalaluddin ◽  
Muh. Setiawan Sukardin
Keyword(s):  
Fluid Flow ◽  
Flow Resistance

Hydrofractures and crustal-scale fluid flow

2021 ◽  
Author(s):  
Paul D. Bons ◽  
Tamara de Riese ◽  
Enrique Gomez-Rivas ◽  
Isaac Naaman ◽  
Till Sachau
Keyword(s):  
Fluid Flow ◽  
Large Scale ◽  
Low Flow ◽  
Fault System ◽  
Tectonic Activity ◽  
Field Evidence ◽  
Dehydration Reactions ◽  
Matrix Flow ◽  
Matrix Porosity ◽  
Fluid Sources

<p>Fluids can circulate in all levels of the crust, as veins, ore deposits and chemical alterations and isotopic shifts indicate. It is furthermore generally accepted that faults and fractures play a central role as preferred fluid conduits. Fluid flow is, however, not only passively reacting to the presence of faults and fractures, but actively play a role in their creation, (re-) activation and sealing by mineral precipitates. This means that the interaction between fluid flow and fracturing is a two-way process, which is further controlled by tectonic activity (stress field), fluid sources and fluxes, as well as the availability of alternative fluid conduits, such as matrix porosity. Here we explore the interaction between matrix permeability and dynamic fracturing on the spatial and temporal distribution of fluid flow for upward fluid fluxes. Envisaged fluid sources can be dehydration reactions, release of igneous fluids, or release of fluids due to decompression or heating.</p><p> </p><p>Our 2D numerical cellular automaton-type simulations span the whole range from steady matrix-flow to highly dynamical flow through hydrofractures. Hydrofractures are initiated when matrix flow is insufficient to maintain fluid pressures below the failure threshold. When required fluid fluxes are high and/or matrix porosity low, flow is dominated by hydrofractures and the system exhibits self-organised critical phenomena. The size of fractures achieves a power-law distribution, as failure events may sometimes trigger avalanche-like amalgamation of hydrofractures. By far most hydrofracture events only lead to local fluid flow pulses within the source area. Conductive fracture networks do not develop if hydrofractures seal relatively quickly, which can be expected in deeper crustal levels. Only the larger events span the whole system and actually drain fluid from the system. We present the 10 square km hydrothermal Hidden Valley Mega-Breccia on the Paralana Fault System in South Australia as a possible example of large-scale fluid expulsion events. Although field evidence suggests that the breccia formed over a period of at least 150 Myrs, actual cumulative fluid duration may rather have been in the order of days only. This example illustrates the extreme dynamics that crustal-scale fluid flow in hydrofractures can achieve.</p>

Experiments on Fluid Flow and Heat Transfer in a Packed Channel Between Two Parallel Grooved Plates

2001 ◽  
Author(s):  
J. H. Du ◽  
B. Ma ◽  
W. Wu ◽  
X. J. Hu ◽  
B. X. Wang
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Resistance ◽  
Direct Consequence ◽  
Contact Condition ◽  
Heated Plate ◽  
Flow And Heat Transfer ◽  
Performance Of Heat Transfer ◽  
Specific Configuration ◽  
Film Heat Transfer

Abstract Experiments on fluid flow and heat transfer in a glass bead packed channel between two parallel grooved plates were conducted. The effects of the grooves on the surface of the heated plate upon the flow resistance and heat transfer were investigated. The results indicated that the grooves on the plate surface change the contact condition of the packed beads to the wall and increase the wall effect of the packed channels. Its direct consequence is to lower the flow resistance. The film heat transfer coefficient on the wall may be increased or rebated. It is demonstrated that a proper combination of packed beads and grooves can lead to the optimum performance of heat transfer for a specific configuration.

Optimization of the lubrication system in a turbocharged engine

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940011
Author(s):  
Cho-Yu Lee ◽  
Dani Joseph Veera ◽  
Huan-Yuan Chen ◽  
Jui-Hung Chang ◽  
Kao-Ruei Hung
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Engine Speed ◽  
System Optimization ◽  
Low Flow ◽  
Lubrication System ◽  
Mechanical Loss ◽  
Oil Pump ◽  
Oil Cooler ◽  
Base Engine

Lubricating the engine reciprocating components effectively against various engine speeds is significant for a proper lubrication system. This paper presents the lubrication system optimization of a twin cylinder 700 c.c. turbocharged engine. A couple of modifications were tested including correction of ducts misalignment, consistence diameter of ducts and replacement of a low flow resistance oil cooler. Compared to the base engine, experimental results prove that differential pressure (DP) between the oil pump and main oil gallery has been decreased to a minimum 19% and maximum 54% at engine speed between 2000 and 7000 rpm. The lower the pressure drop, the lower the flow resistance. Thus, mechanical loss has also been improved.

Hemodynamic functions and blood viscosity in surface hypothermia

1978 ◽  
Vol 235 (2) ◽  
pp. H136-H143 ◽  
Author(s):  
R. Y. Chen ◽  
S. Chien
Keyword(s):  
Body Temperature ◽  
Blood Viscosity ◽  
Flow Resistance ◽  
Plasma Viscosity ◽  
Low Flow ◽  
Flow State ◽  
Surface Cooling ◽  
Plasma Loss ◽  
Pulmonary Flow ◽  
Anesthetized Dogs

Hemodynamic functions and blood viscosity changes in hypothermia (core approximately 25 degrees C) were studied in 14 pentobarbital-anesthetized dogs subjected to surface cooling. The viscosity of blood (eta B) increased progressively to 173% of that at 37 degrees C when body temperature was lowered to 25 degrees C. The increase in blood viscosity was caused by: a) the direct effect of low temperature on plasma viscosity, b) hemoconcentration as a result of plasma loss, and c) the low-flow (low-shear) state induced by hypothermia. A larger portion of the increased viscosity was caused by the low-flow state in hypothermia. The systemic flow resistance (SFR) increased to 271% of control, and this was attributable about equally to the increases in blood viscosity and systemic vascular hindrance (SFR/eta B). Similarly, the viscosity of blood contributed significantly to raising the pulmonary flow resistance. The relative constancy of mixed venous O2 saturation suggests that the cardiac output at low body temperature is generally adequate to meet the metabolic needs

Numerical Analysis of Blockage and Optimization of Heat Transfer Performance of Fractal-like Microchannel Nets

2005 ◽  
Vol 128 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Xiang-Qi Wang ◽  
Arun S. Mujumdar ◽  
Christopher Yap
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Flow Resistance ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Constant Heat Flux ◽  
Low Flow ◽  
Flow And Heat Transfer ◽  
Computational Fluid Dynamics Cfd ◽  
Number Of Branches

The conjugate fluid flow and heat transfer characteristics of fractal-like microchannel nets embedded in a disk-shape heat sink are investigated using a three-dimensional computational fluid dynamics (CFD) approach. A constant heat flux is applied to the top wall of the heat sink. The intrinsic advantages of fractal-like microchannel nets such as low flow resistance, temperature uniformity, and reduced danger of blockage compared with the traditional parallel channel nets are demonstrated. In addition, various optimized designs with parameters such as the number of branches, number of branching levels, and number of channels that reach the center of the disk are addressed in this context.

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