scholarly journals Automobile Radiator’s Engineering and Analysation

2020 ◽  
Vol 9 (5) ◽  
pp. 554-558
Keyword(s):  
Flow Rate ◽  
Heat Dissipation ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Cooling Fan

The shape of a radiator cover is crucial either in determining the pattern of air flow or in increasing the same through the radiator core thereby increasing the thermal efficiency, thus making it a necessity to understand it. Moreover the parts circumjacent to the core namely the upper tank, lower tank, cooling fan, fins, tubes, etc promote the air flow rate. Also it is to note that the air flow rate of discharge gases from radiator core is one of the prime factors in determining the automobile cooling system. Initially factors such as temperature, pressure, air flow rate that affect the performance are obtained in order to derive out the entities of operation. One of the observations that can be made through this paper is that as the volume of the coolant increases, the rate of heat dissipation increases, also parameters like inlet temperature and volume flow rate of coolant, air velocity, temperature drop and drop in pressure of coolant are factors that contribute in radiator performance evidently.

Raised Floor Hybrid Cooled Data Center: Effect on Rack Inlet Air Temperatures When In Row Cooling Units are Installed Between the Racks

2015 ◽  
Author(s):  
Tianyi Gao ◽  
James Geer ◽  
Russell Tipton ◽  
Bruce Murray ◽  
Bahgat G. Sammakia ◽  
...  
Keyword(s):  
Flow Rate ◽  
Data Center ◽  
Heat Load ◽  
Data Centers ◽  
Cooling System ◽  
Air Flow ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Temperatures ◽  
Cooling Unit

The heat dissipated by high performance IT equipment such as servers and switches in data centers is increasing rapidly, which makes the thermal management even more challenging. IT equipment is typically designed to operate at a rack inlet air temperature ranging between 10 °C and 35 °C. The newest published environmental standards for operating IT equipment proposed by ASHARE specify a long term recommended dry bulb IT air inlet temperature range as 18°C to 27°C. In terms of the short term specification, the largest allowable inlet temperature range to operate at is between 5°C and 45°C. Failure in maintaining these specifications will lead to significantly detrimental impacts to the performance and reliability of these electronic devices. Thus, understanding the cooling system is of paramount importance for the design and operation of data centers. In this paper, a hybrid cooling system is numerically modeled and investigated. The numerical modeling is conducted using a commercial computational fluid dynamics (CFD) code. The hybrid cooling strategy is specified by mounting the in row cooling units between the server racks to assist the raised floor air cooling. The effect of several input variables, including rack heat load and heat density, rack air flow rate, in row cooling unit operating cooling fluid flow rate and temperature, in row coil effectiveness, centralized cooling unit supply air flow rate, non-uniformity in rack heat load, and raised floor height are studied parametrically. Their detailed effects on the rack inlet air temperatures and the in row cooler performance are presented. The modeling results and corresponding analyses are used to develop general installation and operation guidance for the in row cooler strategy of a data center.

scholarly journals Optimization of Spray Drying Condition of Asparagus Powder Using Response Surface Methodology (P17-003-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jiseon Park ◽  
Soon Bae Kwon ◽  
Hye Jeong Kwon
Keyword(s):  
Spray Drying ◽  
Flow Rate ◽  
Air Flow ◽  
Absorption Index ◽  
Water Extraction ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Independent Variables ◽  
Drying Conditions ◽  
Spray Dried

Abstract Objectives The purpose of this study was to investigate optimization of spray drying conditions for water-soluble powder using response surface methodology that is a statistical procedure used for optimization studies. Methods First, conditions of the extract used for spray drying were set. We compared heat water extraction (60–100 °C) with ethanol extraction (10–50%). After final selection of the method of extract used for spray drying, spray drying conditions were set. Independent variables included the additive contents of maltodextrin (X1), inlet temperature (X2), and air flow rate (X3). The dependent variables were yield, water absorption index (WAI) and total phenolic compounds. Results The yield was highest in 100 °C heat water extraction. The content of rutin was 29.77 mg/100 g in 90 °C heat water extraction, 28.07 mg/100 g in 100 °C heat water extraction and 24.24 mg/100 g in 10% ethanol extraction. The heat water extraction method at 100 °C was selected as an extract of the spray dryer. Statistical analysis revealed that independent variables significantly affected all the responses. A maximum yield was obtained at 15.55% of X1, 167.87 °C of X2 and 50.00 mL/min of X3. The water absorption index of asparagus increased with increasing MD ratio (X1), higher inlet temperature (X2) and higher air flow rate (X3). The total polyphenol contents of asparagus were higher when the MD addition ratio (X1) was 16.56%, the inlet temperature (X2) was higher and the air flow rate (X3) was higher. Conclusions In this study, extracts of asparagus using different extraction methods were compared for yield and spray-dried asparagus powders were investigated for their physicochemical characteristics. We were vary the range of the temperature, air flow rate, dextrin rate and set the best method for the functionality content of asparagus. Asparagus was spray - dried using 100 °C water extraction with high yield and high rutin content. The maximum spray drying yield was obtained at 15.55% of MD ratio, 167.87 °C of inlet temperature and 50.00 mL/min of air flow rate. There will be additional processed goods development made with what we have found. Funding Sources This study was supported by 2018 Regional Specialized Technology Development Project, Rural Development Administration, Republic of Korea. Supporting Tables, Images and/or Graphs

scholarly journals Numerical Simulation and Optimization of Waste Heat Recovery in a Sinter Vertical Tank

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 385 ◽  
Author(s):  
Chenyi Xu ◽  
Zhichun Liu ◽  
Shicheng Wang ◽  
Wei Liu
Keyword(s):  
Heat Transfer ◽  
Power Consumption ◽  
Flow Rate ◽  
Heat Dissipation ◽  
Waste Heat ◽  
Air Flow ◽  
Particle Diameter ◽  
Exergy Destruction ◽  
Air Flow Rate ◽  
Simulation And Optimization

In this paper, a two-dimensional steady model is established to investigate the gas-solid heat transfer in a sinter vertical tank based on the porous media theory and the local thermal non-equilibrium model. The influences of the air flow rate, sinter flow rate, and sinter particle diameter on the gas-solid heat transfer process are investigated numerically. In addition, exergy destruction minimization is used as a new principle for heat transfer enhancement. Furthermore, a multi-objective genetic algorithm based on a Back Propagation (BP) neural network is applied to obtain a combination of each parameter for a more comprehensive performance, with the exergy destruction caused by heat transfer and the one caused by fluid flow as the two objectives. The results show that the heat dissipation and power consumption both gradually increase with an increase of the air mass flow rate. Additionally, the increase of the sinter flow rate results in a decrease of the heat dissipation and an increase of the power consumption. In addition, both heat dissipation and power consumption gradually decrease with an increase of the sinter particle diameter. For the given structure of the vertical tank, the optimal operating parameters are 2.99 kg/s, 0.61 kg/s, and 32.8 mm for the air flow rate, sinter flow rate, and sinter diameter, respectively.

scholarly journals Thermal Evaluation of a Double-Pass Unglazed Solar Air Heater with Perforated Plate and Wire Mesh Layers

2020 ◽  
Vol 12 (9) ◽  
pp. 3619
Author(s):  
Afaq Jasim Mahmood
Keyword(s):  
Flow Rate ◽  
Thermal Efficiency ◽  
Air Flow ◽  
Wire Mesh ◽  
Inlet Temperature ◽  
Solar Air Heater ◽  
Outlet Temperature ◽  
Air Flow Rate ◽  
Double Pass ◽  
Air Heater

In this study, an experimental outdoor investigation of the thermal efficiency and outlet air temperature was conducted on an unglazed, double-pass, solar air heater with a perforated absorber plate and packing wire mesh layers as a supplemental absorbent area. This was done to observe their effects on the thermal performance of the solar air heater. The double-pass collector was constructed with a bed height of 0.05 m, and a collection area of 1.5 m2. The height of the upper channel was fixed at 0.015 m to improve the thermal efficiency, and the outlet temperature at air flow rates between 0.003 and 0.018 kg/s. The collector was mounted with a slope of 42° facing south, to maximize the intensity of solar irradiance during winter. The effects of the air flow rate, ambient temperature, inlet temperature, outlet temperature, and solar intensity were experimentally investigated. The results showed that thermal efficiency could be improved by increasing the air flow rate, where the highest thermal efficiency achieved was 86% at 0.018 kg/s. However, the temperature difference was increased to a maximum value of 38.6 °C, when the air flow rate was decreased to 0.003 kg/s. Furthermore, the results demonstrated a significant improvement in the thermal efficiency and outlet temperature; and when compared with previous research, the experimental results and the predictions for the outlet temperature using the theoretical model agreed.

Thermal Performance Intensification of Car Radiator using SiO2/Water and ZnO/Water Nanofluids

2021 ◽  
pp. 1-25
Author(s):  
Hussein Maghrabie ◽  
Hamouda Mousa
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Flow Rate ◽  
Thermal Performance ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
The Impact

Abstract Recent progress in nanotechnology has lead to a revolution in the automotive cooling system. In the present work, enhancement of car radiator thermal performance was investigated using different nanofluids named SiO2/water, ZnO/water nanofluids as cooling mediums. The present study mainly aims to investigate the impact of (5 wt.%) from SiO2 and ZnO nanoparticles (NPs) dispersed in water based on car radiator heat transfer with spherical and hexagonal morphology, respectively. The experiments were performed in two working conditions of the nanofluids i.e coolant temperature and volume flow rate, moreover the present results were compared with the previous studies. The experimental working conditions were set at coolant inlet temperature (tc,i) ranged from 45 oC to 80 oC and the coolant volume flow rate (V) ranged from 3.5 lit/min to 6.5 lit/min. The experimental results show that the hexagonal ZnO/water nanofluid was superior towards enhancement of car radiator thermal performance comparing to that of SiO2 NPs. Additionally, at 6.5 lit/min and 45 °C, the enhancements of car radiator effectiveness due to using SiO2 and ZnO based water nanofluids and compared with that for the based water were 13.9% and 16%, respectively. The present study used the multiple regression analysis (MRA) and hence empirical correlations are suggested to estimate the overall heat transfer coefficient (U) for all coolants as functions of volume flow rate (V) and the coolant inlet temperature (tc,i) with a maximum STDEV of ± 1.85%.

Particles Capturing and Correlation with Head Loss in a Pilot-Scale Biological Aerated Filter

2013 ◽  
Vol 409-410 ◽  
pp. 279-286
Author(s):  
Ting Li ◽  
Wen Yi Dong ◽  
Hong Jie Wang ◽  
Jin Nan Lin ◽  
Feng Ouyang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Pilot Scale ◽  
Head Loss ◽  
Biological Aerated Filter ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Lower Velocity ◽  
Aerated Filter ◽  
Filter Bed

Experimental observations of particle capturing through the biological aerated filter bed indicated that air flow rate plays an important role in head loss development by influencing the suspended solids distribution along the depth of the bed as well as the morphology of the deposits. The active height for the SS removal prolonged with the increasing of the air velocity based on the mechanism of first-order kinetics. With the increasing of the superficial air velocity, the effluent SS concentration and the time need to reach the stead-states after backwash both increased. The value of the SS spike in the effluent after backwash at superficial air velocity of 27 m/hr was nearly twice as much as that of 5.4m/hr. Distribution of the deposits at higher air velocity was more uniform. Deposits at lower velocity with air flow rate produced higher head loss gradient. The headloss increased with the increasing of deposits and the increase rate was faster when the deposits exceeded higher value.

scholarly journals Coupling Effect of Air Flow Rate and Operating Conditions on the Performance of Electric Vehicle R744 Air Conditioning System

2021 ◽  
Vol 11 (11) ◽  
pp. 4855
Author(s):  
Anci Wang ◽  
Jianmin Fang ◽  
Xiang Yin ◽  
Yulong Song ◽  
Feng Cao ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Flow Rate ◽  
Air Conditioning ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Volume Flow ◽  
Air Flow Rate ◽  
Air Volume ◽  
Discharge Pressure ◽  
Air Conditioning Systems

The air flow rate on the gas cooler side is one of the key parameters affecting the performance and running safety of transcritical CO2 electric vehicle air conditioning systems. After experimentally analyzing the effects of the air volume flow rate in the gas cooler on the cycle parameters and system performance, a novel method to evaluate the optimal air flow rate was proposed. In addition, the effect of the gas cooler air volume flow rate on the key performance parameters of the system (e.g., optimal discharge pressure) was explored. Finally, the coupling effects of the compressor speed, ambient temperature and optimal air flow rate on the system performance was also exhaustively assessed. It was found that as the discharge temperature, the CO2 temperature at the gas cooler outlet and the discharge pressure did not vary more than ±2%, the corresponding gas cooler air volume flow rate was optimal. For the single-row and dual-process microchannel evaporator used in this work, the recommended value of the optimal gas cooler air volume flow rate was 2500 m3·h−1. The results could provide reference for the fan speed design of electric vehicle CO2 air conditioning systems, especially for the performance under idling model.

Numerical Simulation of Air Flow in BiPV-Trombe Wall

2013 ◽  
Vol 860-863 ◽  
pp. 141-145 ◽  
Author(s):  
Xiao Wei Xu ◽  
Ya Xin Su
Keyword(s):  
Numerical Simulation ◽  
Reynolds Number ◽  
Flow Rate ◽  
Air Flow ◽  
Channel Height ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Trombe Wall ◽  
Multivariable Regression ◽  
Cfd Method

A novel built-in photovoltaic Trombe wall (BiPV-TW) was proposed in this paper and the air flow in a BiPV-Trombe wall was numerically simulated by CFD method. The effect of channel height on flow patterns and air velocity was analyzed. The mass flow rate of air was calculated and a dimensionless expression to calculate the air flow rate in term of a Reynolds number was correlated according to a modified Rayleigh number and the aspect ratio, H/b, which took into account both of the channel sizes and solar radiation based on a multivariable regression analysis.

scholarly journals AIR VELOCITY PROFILES IN AIR BLAST FREEZERS FILLED WITH BOXES OF FRUIT PULP MODELS

2004 ◽  
Vol 3 (2) ◽  
Author(s):  
J.V. Resende ◽  
V. Silveira Jr.
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Relative Difference ◽  
Freezing Process ◽  
Fruit Pulp ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Operation Conditions ◽  
Air Stream ◽  
Pass Through

The changes in the air velocities caused by the resistance for the air flow due to fruit pulp model packaged (100 grams) and conditioned in multi layers boxes during freezing process were evaluated and air flow rate were estimated using a method of treatment of the experimental data. The air velocities were measured before the air pass through the pillage of multi layer boxes in the air stream. For the measurements processing was used a non linear regression routine. Air flow rate measured by the present method resulted of the numerical integration of air velocities adjusted profile. Results presented a relative difference 10 % higher than the standard average procedure, which consists in averaging the air velocity measurements performed at each point of the section. In the same fan operation conditions, the results shown for the 7 layers arrays of product in the boxes which the air velocity was 62% lower than the 3 layers arrays and 50.9 % lower than the 5 layers arrays of product. These results were proportional to the bulk area for the air flow.

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