Cladding Technology for the Outer Circumference of Long Pipes Using the Cooling Function by Ultrafine–bubble–coolant

2020 ◽  
Vol 74 (2) ◽  
pp. 129-132
Author(s):  
Yuuki Shimizu ◽  
Yoichi Shiraishi ◽  
Shinichi Ninomiya
Keyword(s):  
Cooling Function ◽  
Outer Circumference

Friction of outer rotor affecting friction torque characteristics in an internal gear pump

2014 ◽  
Vol 229 (16) ◽  
pp. 3013-3026 ◽  
Author(s):  
Yoshiharu Inaguma
Keyword(s):  
Pressure Distribution ◽  
Friction Force ◽  
Significant Loss ◽  
Friction Torque ◽  
The Body ◽  
Gear Pump ◽  
Suction Pressure ◽  
Outer Rotor ◽  
Internal Gear ◽  
Outer Circumference

This article presents the friction torque in an internal gear pump and the friction force between an outer circumference of an outer rotor and a body, which causes a significant loss, has been investigated. When in use at a high pressure, the pump has a large friction torque due to the friction force acting on the outer rotor circumference. This friction force is caused by imbalanced force acting on the outer rotor. As well as by a positioning suction and a delivery port, the force can be reduced by setting a suction pressure recess in a section of the outer rotor circumference. In this study, through the measurement of the friction torque in an actual pump and the pressure distribution on the outer circumference of the outer rotor, it is investigated how the suction pressure recess can change the force acting on the outer rotor. The actual internal gear pump without the suction pressure recess has a large friction torque, and it corresponds to a large force on the outer rotor, which is calculated from the pressure distributions on the inside and outside of the outer rotor. In addition, on the basis of the measured friction torque of the test pump and the force acting on the outer rotor, calculated using the results of the pressure distribution, the coefficient of friction between the outer rotor circumference and the body can be estimated.

scholarly journals An apparatus for liquid measurement by drops and applications in counting bacteria and other cells and in serology, etc

1913 ◽  
Vol 86 (586) ◽  
pp. 198-202 ◽  
Keyword(s):  
Constant Pressure ◽  
Fundamental Principle ◽  
Simple System ◽  
Liquid Measurement ◽  
Outer Circumference

To promote drop-measuring in serological and bacteriological work, etc., the writer has devised a simple system of producing uniform pipettes, clean and sterile, which deliver uniform drops of any required size from ¼ c. c. down to 1/200 c. c. or less, and has devised also simple forms of constant-pressure apparatus for use with the pipettes. The fundamental principle of his method rests on the fact that the size of a drop of a given liquid yielded by a clean pipette is determined by the outer circumference of the pipette at the level where the contact-edge of the drop clings round the glass—due allowance being made for the rate at which the drop is detached and the temperature.

scholarly journals A Comparative Analysis of Thermoelectric Modules for the Purpose of Ensuring Thermal Comfort in Protective Clothing

2021 ◽  
Vol 11 (17) ◽  
pp. 8068
Author(s):  
Anna Dąbrowska ◽  
Monika Kobus ◽  
Bartosz Pękosławski ◽  
Łukasz Starzak
Keyword(s):  
Heat Flux ◽  
Ambient Temperature ◽  
Heat Sink ◽  
Protective Clothing ◽  
Phase Change Materials ◽  
Thermoelectric Module ◽  
Thermoelectric Modules ◽  
Cooling Function ◽  
A Tec ◽  
Flexible Thermoelectric

In recent times, more and more workers are exposed to thermal stress due to climate changes and increased ambient temperature. Demanding physical activities and the use of protective clothing are additional sources of thermal load for workers. Therefore, recent research has focused on the development of protective clothing with a cooling function. Phase change materials, air or liquid, were mainly used for this purpose; only a few publications were concerned the use of thermoelectric modules. This publication analyzes the influence of such factors as supplied current, ambient temperature, and the type of heat sink on the amount of heat flux transferred by a thermoelectric cooler (TEC) and the electric power consumed by it. In the course of laboratory tests, a flexible thermoelectric module and three heat sink variants were tested. For this purpose, a polymer TEGway heat sink, a metal one, and a self-made one based on a superabsorbent were used. The research showed that at a temperature of 30 °C and above, the amount of the heat flux transferred by a TEC with a total area of 58 cm2, and an active area of 10 cm2 should be expected to be from 1 W to 1.5 W. An increase in ambient temperature from 20 to 35 °C caused a significant reduction in the heat flux by about 1 W. The results obtained indicated that the type of heat sink affects the heat flux drawn by the TEC to a statistically significant extent. The heat sink using the evaporation effect turned out to be the most efficient.

scholarly journals A thermally stable aerostatic spindle system equipped with self-cooling function

2014 ◽  
Vol 8 (6) ◽  
pp. JAMDSM0079-JAMDSM0079 ◽  
Author(s):  
Yuuki TAMURA ◽  
Hiroshi SAWANO ◽  
Hayato YOSHIOKA ◽  
Hidenori SHINNO
Keyword(s):  
Thermally Stable ◽  
Spindle System ◽  
Cooling Function ◽  
Aerostatic Spindle

scholarly journals Cooling flow solutions for the circumgalactic medium

2019 ◽  
Vol 488 (2) ◽  
pp. 2549-2572 ◽  
Author(s):  
Jonathan Stern ◽  
Drummond Fielding ◽  
Claude-André Faucher-Giguère ◽  
Eliot Quataert
Keyword(s):  
Galaxy Formation ◽  
Milky Way ◽  
High Redshift ◽  
Formation Rate ◽  
Free Fall ◽  
Cooling Time ◽  
Cooling Flow ◽  
Similar Solutions ◽  
Cooling Function ◽  
Milky Way Halo

ABSTRACT In several models of galaxy formation feedback occurs in cycles or mainly at high redshift. At times and in regions where feedback heating is ineffective, hot gas in the galaxy halo is expected to form a cooling flow, where the gas advects inward on a cooling timescale. Cooling flow solutions can thus be used as a benchmark for observations and simulations to constrain the timing and extent of feedback heating. Using analytic calculations and idealized 3D hydrodynamic simulations, we show that for a given halo mass and cooling function, steady-state cooling flows form a single-parameter family of solutions, while initially hydrostatic gaseous haloes converge on one of these solutions within a cooling time. The solution is thus fully determined once either the mass inflow rate ${\dot{M}}$ or the total halo gas mass are known. In the Milky Way halo, a cooling flow with ${\dot{M}}$ equal to the star formation rate predicts a ratio of the cooling time to the free-fall time of ∼10, similar to some feedback-regulated models. This solution also correctly predicts observed $\rm{O\,{\small VII}}$ and $\rm{O\,{\small VIII}}$ absorption columns, and the gas density profile implied by $\rm{O\,{\small VII}}$ and $\rm{O\,{\small VIII}}$ emission. These results suggest ongoing heating by feedback may be negligible in the inner Milky-Way halo. Extending similar solutions out to the cooling radius however underpredicts observed $\rm{O\,{\small VI}}$ columns around the Milky-Way and around other low-redshift star-forming galaxies. This can be reconciled with the successes of the cooling flow model with either a mechanism which preferentially heats the $\rm{O\,{\small VI}}$-bearing outer halo, or alternatively if $\rm{O\,{\small VI}}$ traces cool photoionized gas beyond the accretion shock. We also demonstrate that the entropy profiles of some of the most relaxed clusters are reasonably well described by a cooling flow solution.

scholarly journals Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Anna Perelomova
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Open System ◽  
Nonlinear Effects ◽  
Nonlinear Phenomena ◽  
Direct And Inverse Problems ◽  
Radiation Losses ◽  
Magnetoacoustic Waves ◽  
Magnetic Strength ◽  
Cooling Function

The nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode in the field of intense magnetoacoustic perturbations is the result of special projecting of the conservation equations in the differential form. It is analyzed in some physically meaningful cases; those are periodic magnetoacoustic perturbations and particular cases of heating-cooling function. A plasma is situated in the straight magnetic field with constant equilibrium magnetic strength which form constant angle with the direction of wave propagation. A plasma is initially uniform and equilibrium. The conclusions concern nonlinear effects of fast and slow magnetoacoustic perturbations and may be useful in direct and inverse problems.

Numerical Simulation of Temperature Profile in a Compartment Fire with a Roof Opening

2012 ◽  
Vol 538-541 ◽  
pp. 989-992 ◽  
Author(s):  
Jin Mei Li ◽  
Qiang Li ◽  
Yan Lei Dong ◽  
Chang Hai Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Temperature Profile ◽  
Source Size ◽  
Temperature Profiles ◽  
Compartment Fire ◽  
Gas Temperature ◽  
Fire Source ◽  
Smoke Layer ◽  
Cooling Function

Fifteen numerical simulations are presented in this article to investigate the influence of roof opening size and fire source size on gas temperature profiles in a compartment. The fire source size has a significant impact on the temperature hot smoke layer. The temperature of hot smoke layer increases as the increase of fire source size. The roof opening has cooling function to gas temperature in the compartment especially for large roof opening. The temperatures of hot smoke layer decrease with the roof opening size increase in all cases.

Three-Dimensional Flow Near the Blade/Endwall Junction of a Gas Turbine: Application of a Boundary Layer Fence

1991 ◽  
Author(s):  
J. T. Chung ◽  
T. W. Simon ◽  
J. Buddhavarapu
Keyword(s):  
Boundary Layer ◽  
Gas Turbine ◽  
Film Cooling ◽  
Three Dimensional ◽  
Horseshoe Vortex ◽  
Management Technique ◽  
Suction Surface ◽  
Cooling Flow ◽  
Passage Vortex ◽  
Cooling Function

A flow management technique designed to reduce some harmful effects of secondary flow in the endwall region of a turbine passage is introduced. A boundary layer fence in the gas turbine passage is shown to improve the likelihood of efficient film cooling on the suction surface near the endwall. The fence prevents the pressure side leg of the horseshoe vortex from crossing to the suction surface and impinging on the wall. The vortex is weakened and decreased in size after being deflected by the fence. Such diversion of the vortex will prevent it from removing the film cooling flow allowing the flow to perform its cooling function. Flow visualization on the suction surface and through the passage shows the behavior of the passage vortex with and without the fence. Laser Doppler velocimetry is employed to quantify these observations.

Liquid-Coupled Indirect-Transfer Exchanger Application to the Diesel Engine

1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling System ◽  
Relative Effectiveness ◽  
Ambient Air ◽  
Air Cooling ◽  
Performance Curves ◽  
Air Cooling System ◽  
Cooling Function ◽  
Low Charge

The efficiency of turbocharged diesel engines can be increased by cooling the charge air. This paper presents a design approach for liquid-coupled indirect-transfer heat exchanger systems to perform the air-cooling function. The two advantages most commonly cited for this approach to charge-air cooling are (1) the heat exchangers involved are easily packaged so that their shapes can be controlled by judicious design, and (2) simple gas ducting allows for compact machinery arrangements and relatively low charge-air pressure drop. An analytical approach to the design of liquid-coupled indirect-transfer heat exchanger systems is presented. Performance curves are constructed on the basis of this analysis. Four important design conditions are evident from the observation of these performance curves including (1) the relative capacity rate combination of the three fluids (ambient air, coupling liquid, and engine charge-air) which yields the highest overall effectiveness, (2) an optimum coupling-liquid flow rate, (3) the relative effectiveness distribution for each of the two component heat exchangers (hot and cold components), and (4) a broad design range for the optimum area distribution between the hot and cold exchangers. These performance curves serve as a guide for the design of a liquid-coupled charge-air cooling system.

Sign in / Sign up

Export Citation Format

Share Document