scholarly journals Performance comparison of various coolants for louvered fin tube automotive radiator

2017 ◽  
Vol 21 (6 Part B) ◽  
pp. 2871-2881 ◽  
Author(s):  
Rashmi Sahoo ◽  
Pradyumna Ghosh ◽  
Jahar Sarkar
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Fuel Consumption ◽  
Propylene Glycol ◽  
Sugarcane Juice ◽  
Engine Fuel ◽  
Pumping Power ◽  
Power Requirement ◽  
Engine Efficiency ◽  
Louvered Fin

In the present study, screening of various coolants (water, ethylene glycol, propylene glycol, brines, nanofluid, and sugarcane juice) for louvered fin automotive radiator has been done based on different energetic and exergetic performance parameters. Effects on radiator size, weight and cost as well as engine efficiency and fuel consumption are discussed as well. Results show that the sugarcane juice seems to be slightly better in terms of both heat transfer and pumping power than water and nanofluid, whereas significantly better than ethylene glycol and propylene glycol. For same heat transfer capacity, the pumping power requirement is minimum and vice-versa with sugarcane juice, followed by nanofluid, water, EG and PG. Study on brines shows an opportunity to use water+25% PG based nanofluids for improvement of performance as well as operating range. Replacement of water or brines by using sugarcane juice and water or wa-ter+25% PG based nanofluids will reduce the radiator size, weight and pumping power, which may lead to increase in compactness and overall engine efficiency or reduction in radiator cost and engine fuel consumption. In overall, both sugarcane juice and nanofluid seem to be potential substitutes of water. However, both have some challenges such as long term stability for practical use.

Performance Analysis of Single-Phase Space Thermal Radiators and Optimization through Taguchi-Neuro-Genetic Approach

2021 ◽  
pp. 1-18
Author(s):  
P B Chiranjeevi ◽  
Ashok V ◽  
K. Srinivasan ◽  
Thirumalachari Sundararajan
Keyword(s):  
Heat Transfer ◽  
Performance Analysis ◽  
Conjugate Heat Transfer ◽  
Computational Time ◽  
Maximum Diameter ◽  
Genetic Approach ◽  
Pumping Power ◽  
Power Requirement ◽  
Space Applications ◽  
Heat Rejection

Abstract In the thermal management of spacecraft, space thermal radiators play a vital role as heat sinks. A serial radiator with proven advantages in ground applications is proposed and analyzed for space applications. From the performance analysis, specific heat rejection of serial radiator is found to be higher than parallel radiator by 80% for maximum diameter of tube, 47% for maximum thickness of fin, and 75% for maximum pitch of tubes under consideration. Also, serial radiator requires four times higher pumping power than parallel radiator with geometric parameters and a maximum mass flow rate under consideration. In serial radiators, the cross conduction between the fins has a significant effect on its thermal performance. Thus, conjugate heat transfer simulations and optimization operations are to be performed iteratively to optimize the serial radiator, which is computationally costly. To reduce the computational time, Artificial Neural Network is trained using conjugate heat transfer simulations data and combined with the genetic algorithm to perform optimization. Taguchi's orthogonal arrays provided the partial fraction of conjugate heat transfer simulations set to train the ANN. Taguchi-Neuro-Genetic approach, a process that combines the features of three powerful techniques in different optimization phases, is used to optimize both parallel and serial radiators. The optimization aims to obtain a configuration that provides the lowest mass and lowest pumping power requirement for given heat rejection. Optimization results show that the conventional parallel radiator is about 20% heavier and requires about 35% more pumping power than the proposed serial radiator.

Convective Heat Transfer and Pumping Power Requirement Using Nanofluid for the Flow Through Corrugated Channel

2015 ◽  
Author(s):  
Shafi Noor ◽  
M. Monjurul Ehsan ◽  
M. S. Mayeed ◽  
A. K. M. Sadrul Islam
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Heat Transfer Rate ◽  
Convective Heat ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Pumping Power ◽  
Power Requirement ◽  
Corrugated Channel ◽  
Flow Through

Convective heat transfer rate for turbulent flow using nanofluid through both plain and corrugated channel has been investigated numerically in the present study. Three different types of nanofluids namely Al2O3-water, TiO2-water and CuO-water of different volume fractions (1%, 2%, 3%, 4% and 5%), are used as the working fluid flowing through the channel. The corrugated channels have wall geometries of trapezoidal shape of different amplitude-wavelength ratios. Grid independence study was carried out for all the geometries. The obtained results in case of base fluid-water flowing through parallel plate channel have been validated with well-established correlations. The study has been conducted by finite volume method to solve the transport equation for the momentum, energy and turbulence quantities using single phase model of the nanofluids where the thermophysical properties of the nanofluids are calculated by using different correlations from the literature. In this study, the heat transfer enhancement using nanofluids compared to that using base fluid-water is presented for a range of Reynolds number- 15000 to 40000. The pumping power required for the flow through the channels increases with the increase in the viscosity of the fluid which justifies the increase in pumping power requirement in case of nanofluids compared to that with water. While using corrugation at the wall of the channels, in addition to the enhancement in the convective heat transfer rate, there is an increase in the pumping power requirement for the same Reynolds number. However, for a given requirement of heat transfer rate, the required pumping power can be reduced by using nanofluids. This study includes the trend and limit of volume fraction of nanofluid during this pumping power reduction phenomenon. The results show that with the increase in the volume fraction of the nanofluids, the convective heat transfer rate increases which is same for all the geometries of the fluid domain. Addition of nanofluid reduces the pumping power requirement for a constant heat transfer rate. The volume fraction of the nanofluids with which the maximum reduction of pumping power takes place at the optimum working condition is also found in the present study. This study draws a comparison among three different nanofluids in terms of the enhancement in the convective heat transfer rate and corresponding pumping power requirement for the flow through the trapezoidal shaped corrugated channel of various amplitude-wavelength ratios in order to find out the best nanofluids for its optimum results within a specified range of working conditions.

Homogeneous Engine Cooling: An Efficient Cross-Cooling Strategy — CFD Analysis and Measurements

2002 ◽  
Author(s):  
S. Etemad
Keyword(s):  
Heat Transfer ◽  
Fuel Economy ◽  
Cfd Analysis ◽  
Engine Test ◽  
Pumping Power ◽  
Test Bed ◽  
Engine Efficiency ◽  
Cooling Strategy ◽  
Engine Cooling ◽  
Ic Engines

A new precision cross-cooling strategy is developed for IC-engines to contribute to lower exhaust emissions, better fuel-economy, better engine durability and compact packaging. The heat transfer is increased by 40% in the inter-bore regions and by 160% on the exhaust valve-bridges. The cylinders are also cooled more equally. The pressure drop decreased by 26% and the flow increased by 60%. The pumping power for the whole system decreased by 9% and in addition due to some 4% reduction of thermal waste, up to 2% improvement in engine efficiency can be assumed. Increased flow also facilities enhanced performance for the radiator and cab-heater. The investigation was done by CFD and verified by measurements in engine test-bed. By displaying up to 28°C decrease in the inter-bore region and up to 15°C decrease in the valve-bridge region, the tests confirmed the CFD-predicted improvements.

Nucleate Boiling Performance of Azeotropic Binary Mixtures in a Saturate Pool Boiling System

2010 ◽  
Author(s):  
Kunihito Matsumura ◽  
Fumito Kaminaga
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Binary Mixtures ◽  
Pure Water ◽  
Prediction Method ◽  
Nucleate Boiling ◽  
Transfer Coefficients ◽  
Process Industries ◽  
Nucleate Boiling Heat Transfer

Nucleate boiling of binary mixtures is of particular importance in chemical and process industries. The purpose of the present study is to provide experimental data and prediction method for nucleate boiling heat transfer in two types of anti-freeze solutions, Propylene-glycol (PG)/water and Ethylene-glycol (EG)/water, under atmospheric pressure. The experiments were performed in a saturated condition. The concentrations of solutions are varied from 10 to 40 wt%. It was found that the heat transfer coefficient gradually decreases as increasing the addition of anti-freeze. An addition of small amount of propylene-glycol and ethylene-glycol to water also decreases the CHF value far below that of pure water. It is concluded that the correlation proposed by Fujita for several binary mixtures can well predict the heat transfer coefficients within almost ±5% accuracy for every concentration of mixture solutions.

Design Optimisation of Finned Channel

2009 ◽  
Author(s):  
K. M. C. Seakher ◽  
L. S. S. Prakash Kumar ◽  
K. S. R. Kali Prasad ◽  
K. H. Manasa ◽  
A. Siva Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Dissipation ◽  
Pumping Power ◽  
Transfer Enhancement ◽  
Power Requirement ◽  
Smooth Channel ◽  
Fin Length

A finned channel has a higher heat transfer coefficient compared to a smooth channel and the increase in this fin height enhances the heat transfer. But this heat transfer enhancement is accompanied by an increase in pressure drop for a series of fins. This requires an increase in pumping power requirement, indicating that there exists an optimum design or length of the fin at which the heat dissipation is maximum. The objective of this paper is to observe the variation of heat transfer with varying sizes of fins. The effect of fin dimensions on heat transfer can be clearly seen in its performance, which is discussed in the paper. The results are obtained by analytical analysis, and some illustrations are dealt with in the paper, which clearly determine the importance of this factor of optimal fin length.

Numerical Heat Transfer and Pressure Drop Studies of Turbulent Al2O3 - Ethylene Glycol/Water Nanofluid Flow in an Automotive Radiator Tube

2015 ◽  
Vol 787 ◽  
pp. 152-156 ◽  
Author(s):  
N. Mohanrajhu ◽  
K. Purushothaman ◽  
N. Kulasekharan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Ethylene Glycol ◽  
Base Fluid ◽  
Unit Length ◽  
Thermal Characteristics ◽  
Turbulent Regime ◽  
Pumping Power ◽  
Numerical Heat Transfer ◽  
Nano Fluid

Automotive radiators use flattened tubes within which Ethylene Glycol (EG) and Water (W) based nanofluids flow to enhance the heat transfer. Computations were carried out to understand the flow and thermal characteristics of the Aluminium oxide based nanofluids, with EG:W ratio of 60:40 as the base fluid, flowing inside a flattened tube. The flow was maintained in the turbulent regime with the Reynolds number (Re) ranging from 5,000 to 14,000.Investigations were carried out for nano particle concentrations (φ) varying from 1% to 5% of the base fluid by volume. Computations were also carried out for a circular tube to study the influence of tube shape. The nanofluid with φ = 5% increased the Nusselt number values by 40% for the flattened tubes compared to the base fluid at Re =14,000. These estimates are done at constant flow Reynolds number in-line with literature, which necessitated increased inlet velocity, which meant increased pumping power. Pumping power increased with increase in φ and Re. For a constant pumping power per unit length (Pp) of 5W/m the values of average heat transfer coefficient () decreases with increase in φ. The values of for the 2% and 5% nano fluid were lower than the base fluid by 6% and 23.8% respectively. Nanofluid with φ = 1% alone showed a 1.2% higher value than the base fluid indicating the need of further exploration of φ in a closer range.

Heat transfer and second law analysis of ethylene glycol based ternary hybrid nanofluid under laminar flow

2021 ◽  
pp. 1-45
Author(s):  
Lingala Sundar ◽  
Kottutu V.V. Chandra Mouli ◽  
Zafar Said ◽  
Antonio C.M. Sousa
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Laminar Flow ◽  
Ethylene Glycol ◽  
Physical Properties ◽  
Friction Factor ◽  
Base Fluid ◽  
Hybrid Nanofluid ◽  
Pumping Power ◽  
Thermo Physical Properties

Abstract Experiments were conducted to evaluate the thermal and frictional entropy generation and exergy efficiency of rGO-Fe3O4-TiO2 hybrid nanofluid in a circular tube under laminar flow. The ternary nanoparticles are synthesized using the sol-gel technique and characterized by XRD, SEM, and FTIR. The stable ethylene glycol based ternary hybrid nanofluid were prepared and thermo-physical properties, heat transfer, friction factor, and pumping power at various particle weight concentrations (0.05% to 0.2%) and Reynolds number (211 to 2200) were investigated. Enhancement in the thermal conductivity and viscosity of 10.6% and 108.3% at ψ = 0.2% and at 60°C over the base fluid were obtained. Similarly, Nusselt number is enhanced to 17.78%; heat transfer coefficient is enhanced to 24.76%; thermal entropy generation is reduced to 19.85%; exergy efficiency enhancement of 6.23% at ψ = 0.2% and at Re = 1548 is achieved. The pressure drop, pumping power, and friction factor is augmented to 13.65%, 11.33%, and 16% at ψ = 0.2% and at Re = 221.1 over the base fluid. The overall thermal performance of the system is enhanced to 14.32%. New equations are modeled to evaluate the thermo-physical properties, Nusselt number, and friction factor.

An Air-Based Cavity-Receiver for Solar Trough Concentrators

2010 ◽  
Author(s):  
Roman Bader ◽  
Maurizio Barbato ◽  
Andrea Pedretti ◽  
Aldo Steinfeld
Keyword(s):  
Heat Transfer ◽  
Solar Power ◽  
Power Input ◽  
Absorption Efficiency ◽  
Conservation Equation ◽  
Heat Transfer Fluid ◽  
Inlet Temperature ◽  
Transfer Model ◽  
Pumping Power ◽  
Power Requirement

A cylindrical cavity-receiver containing a tubular absorber that uses air as the heat transfer fluid is proposed for a novel solar trough concentrator design. A numerical heat transfer model is developed to determine the receiver’s absorption efficiency and pumping power requirement. The 2D steady-state energy conservation equation coupling radiation, convection and conduction heat transfer is formulated and solved numerically by finite-difference techniques. The Monte Carlo ray-tracing and radiosity methods are applied to establish the solar radiation distribution and radiative exchange within the receiver. Simulations were conducted for a 50 m-long and 9.5 m-wide collector section with 120°C air inlet temperature, and air mass flows in the range 0.1–1.2 kg/s. Outlet air temperatures ranged from 260 to 601 °C, and corresponding absorption efficiencies varied between 60 and 18%. Main heat losses integrated over the receiver length were due to reflection and spillage at the receiver’s windowed aperture, amounting to 13% and 9% of the solar power input, respectively. The pressure drop along the 50 m module was in the range 0.23 to 11.84 mbar, resulting in isentropic pumping power requirements of 6.45·10−4%–0.395% of the solar power input.

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