Fluid Motion and Heat Transfer of a High-Viscosity Fluid in a Rectangular Tank on a Ship With Oscillating Motion

1987 ◽  
Vol 109 (3) ◽  
pp. 635-641 ◽  
Author(s):  
S. Akagi ◽  
K. Uchida
Keyword(s):  
Heat Transfer ◽  
Numerical Solutions ◽  
Fluid Motion ◽  
Heating System ◽  
High Viscosity ◽  
Thermal Design ◽  
Basic Equations ◽  
Oil Tanks ◽  
Oscillating Motion ◽  
Viscosity Fluid

Fluid motion and heat transfer of a high-viscosity fluid contained in a two-dimensional rectangular ship’s tank subjected to oscillating motion are investigated by a finite difference technique. The study is motivated by the thermal design of the heating system of oil tanks on a tanker which is moving in a wavy sea. The bottom of the tank is heated and its side walls are cooled. The motion of the tank is assumed to be a simple harmonic rolling motion. The isotherms and flow velocity vectors are determined by numerical solutions of the basic equations describing the convection flows in a tank with oscillating motion. The heat transfer rates to the tank walls are predicted. The influence of the frequency of the oscillating motion on the heat transfer rate is examined.

scholarly journals Research on the Heating of Deicing Fluid in a New Reshaped Coiled Tube

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mengli Wu ◽  
Chiyu Wang ◽  
Yunpeng Li ◽  
Qi Nie
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Heating System ◽  
High Viscosity ◽  
Negative Influence ◽  
Heating Time ◽  
Temperature Fields ◽  
Outlet Temperature ◽  
Coiled Tube ◽  
Deicing Fluid

Aircraft ground deicing operation is significant to ensure civil flight safety in winter. Helically coiled tube is the important heat exchanger in Chinese deicing fluid heating system. In order to improve the deicing efficiency, the research focuses on heat transfer enhancement of deicing fluid in the tube. Based on the field synergy principle, a new reshaped tube (TCHC) is designed by ring-rib convex on the inner wall. Deicing fluid is high viscosity ethylene-glycol-based mixture. Because of the power function relation between high viscosity and temperature, viscosity has a negative influence on heat transfer. The number of ring-ribs and inlet velocity are two key parameters to the heat transfer performance. For both water and ethylene glycol, the outlet temperature rises when the number of ring-ribs increases to a certain limit. However, the increasing of velocity reduces heating time, which results in lower outlet temperature. The heating experiment of the original tube is conducted. The error between experiment and simulation is less than 5%. The outlet temperature of TCHC increases by 3.76%. As a result, TCHC efficiently promotes the coordination of velocity and temperature fields by changing the velocity field. TCHC has enhanced heat transfer of high viscosity deicing fluid.

Unsteady Hydromagnetic Generalized Couette Flow of a Non-Newtonian Fluid With Heat Transfer Between Parallel Porous Plates

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Hazem Ali Attia ◽  
Mohamed Eissa Sayed-Ahmed
Keyword(s):  
Heat Transfer ◽  
Numerical Solutions ◽  
Fluid Motion ◽  
Casson Fluid ◽  
Lower Plate ◽  
Plate Temperature ◽  
Electrically Conducting ◽  
Energy Equations ◽  
External Uniform Magnetic Field ◽  
Newtonian Behavior

The unsteady magnetohydrodynamics flow of an electrically conducting viscous incompressible non-Newtonian Casson fluid bounded by two parallel nonconducting porous plates is studied with heat transfer considering the Hall effect. An external uniform magnetic field is applied perpendicular to the plates and the fluid motion is subjected to a uniform suction and injection. The lower plate is stationary and the upper plate is suddenly set into motion and simultaneously suddenly isothermally heated to a temperature other than the lower plate temperature. Numerical solutions are obtained for the governing momentum and energy equations taking the Joule and viscous dissipations into consideration. The effect of the Hall term, the parameter describing the non-Newtonian behavior, and the velocity of suction and injection on both the velocity and temperature distributions are studied.

A Comprehensive Heat Transfer Study Inside a Steam Turbine Valve: Experiment, Numerical Simulation and Simplified Model

2021 ◽  
Author(s):  
Xu Zhang ◽  
Hongyi Shao ◽  
Wenwu Zhou ◽  
Wei Zhe Wang ◽  
YingZheng Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Steam Turbine ◽  
Transfer Process ◽  
Electric Heating ◽  
Heating System ◽  
Heat Transfer Process ◽  
Thermal Design ◽  
Simplified Model ◽  
Operational Flexibility

Abstract In a steam turbine system, one of the main factors limiting the operational flexibility is the thermal stress associated with a high temperature gradient within the control valves, which often leads to structural damage during frequent start-up and shut-down cycles. One possible solution is to utilize an electric heating system with appropriate insulation to decrease the warm-up time. Here, an experiment and a numerical simulation were performed using a scaled turbine valve equipped with an electric heating system to understand the heat transfer process. The experiment was conducted at Shanghai Jiao Tong University and had a duration of 100 hours, including three heating-cooling cycles and two heat preservation states. The simulation, which used the commercial software Ansys Fluent 2019 R1 with the finite volume method, was performed to model the experimental heat transfer process. The simulated results showed less than 10% deviation from the measured temperatures. To further improve the computing efficiency, a simplified model based on the lumped parameter method was proposed and validated. This model can predict the valve temperature in less than 1 minute and showed good agreement for all of the studied cases. The ability of the simplified model to simulate the valve heating-cooling cycles at a high efficiency could accelerate the thermal design process to improve the operational flexibility of steam turbines in the future.

Electrocaloric cooling prototype using lead-free barium titanate multilayer capacitors and heat transfer fluid motion

2021 ◽  
pp. 1-17
Author(s):  
Said Bellafkih ◽  
Abdelhak Hadj-Sahraoui ◽  
Pierre Kulinski ◽  
Pierre Dumoulin ◽  
Stephane Longuemart
Keyword(s):  
Heat Transfer ◽  
Barium Titanate ◽  
Fluid Motion ◽  
Lead Free ◽  
Heat Transfer Fluid ◽  
Refrigeration Cycle ◽  
Electrocaloric Effect ◽  
Multilayer Capacitors ◽  
Oscillating Motion

Abstract In this paper, we describe the realisation and the testing of an electrocaloric effect based refrigeration prototype. The prototype makes use of Active Electrocaloric Regenerator (AER) made of commercially available MultiLayer ceramics and exploits the oscillating motion of a heat transfer fluid in a thermodynamic refrigeration cycle. The setup allows the adjustment of various parameters and the effect of the frequency of the cycle as well as the volume displaced of the heat transfer fluid has been evidenced. An amplification regenerative factor of 1.25 has been reached, comparable and slightly higher to those of previously proposed electrocaloric refrigerator prototypes.

scholarly journals Computational Analysis of Heat Transfer Intensification of Fractional Viscoelastic Hybrid Nanofluids

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Mumtaz Khan ◽  
Amer Rasheed
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Electric Fields ◽  
Computational Analysis ◽  
Numerical Solutions ◽  
Numerical Technique ◽  
Fluid Motion ◽  
Convection Heat Transfer ◽  
Point Of View ◽  
Hybrid Nanofluid

In the current article, we have performed computational analysis on convection heat transfer of a hybrid nanofluid in occurrences where porous media and the effect of magnetic force are involved. In order to assess the time-fractional derivatives, Caputo’s notion is utilized while the Darcy–Forchheimer model is applied due to the involvement of the porous medium. Moreover, the boundary conditions are assumed to be nonuniform through the equilibrium between the surface tension and shear stress over a semi-infinite permeable flat surface. Keeping in view the complexity of the fractional derivative model and nonuniform boundary conditions, the problem in question is a complicated one. Accordingly, the coupled momentum and energy equation is linearized and the finite difference scheme is then applied and implemented in MATLAB Code R2020b. Furthermore, we have also offered a comprehensive analysis regarding error and convergence of the proposed numerical method. The newly introduced numerical technique to determine the numerical solutions and some unique and interesting deductions are established. From the computational results, one can conclude that the fluid motion in both hybrid and single nanofluids slows down due to magnetic field, porosity, and inertia coefficient as the magnetic and electric fields are synchronized due to the formation of the Lorentz force and viscous interference. We believe that our proposed numerical technique regarding employment of the fractional model for heat transfer application to the hybrid nanofluid over a semi-infinite nonuniform permeable surface along with variable heat flux is not found in the literature so far. Furthermore, the obtained results will be a valuable addition to fractional calculus from an engineering point of view.

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

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