Variation of Exit Flow Velocity according to Various Inlet Temperature and Air Flow Rate against Fan Heater

2018 ◽  
Vol 22 (2) ◽  
pp. 95-102
Author(s):  
Kwang-Ho Lee ◽  
Ki-Woo Nam ◽  
Seok-Hwan Ahn
Keyword(s):  
Flow Velocity ◽  
Flow Rate ◽  
Air Flow ◽  
Inlet Temperature ◽  
Air Flow Rate

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.

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

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 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.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Modeling and optimization of radish root extract drying as peroxidase source using spouted bed dryer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Air Flow ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Air Flow Rate ◽  
Spouted Bed ◽  
Radish Root

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

Method to Determine an Optimal Air-Flow Rate in Solar Collectors

1979 ◽  
Vol 3 (6) ◽  
pp. 357-362
Author(s):  
H. C. Hewitt ◽  
E. I. Griggs
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Solar Collectors ◽  
Air Flow Rate
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