scholarly journals HVAC CFD Analysis of Air Flow and Temperature Distribution Inside Passenger Compartment

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhamad Haziq Mohammad Aris ◽  
◽  
Nofrizalidris Darlis ◽  
Izuan Amin Ishak ◽  
Syabillah Sulaiman ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Thermal Environment ◽  
Air Flow ◽  
Spatial And Temporal Variation ◽  
State Variables ◽  
Clothing Insulation ◽  
Vehicle Cabin ◽  
Air Blower ◽  
Good Agreement

The thermal environment and air quality in a passenger car can affect driver's and passengers' health, performance and comfort. Due to spatial and temporal variation of state variables and boundary conditions in the vehicle cabin, the heating, ventilating and air-conditioning (HVAC) does not have to be designed to provide a uniform environment. This are due to individual differences regarding to physiological and psychological response, clothing insulation, activity, air temperature and air movement preference. Experimental study in vehicle HVAC system can be very costly to be conducted. In order to analyze the air flow and temperature distribution in passengers compartment, a numerical simulation was used in this study to analyze the air flow and temperature distribution of HVAC unit inside Proton Exora passengers compartment, with the air blower speed and air temperature used as parameter, to evaluate the airflow behavior and temperature distribution in the compartment. The simulation data obtained is then compared to the experimental data, showing good agreement between these two methods.

Temperature Distribution of Hot Air Flow in Heating Zone for Drying Application

2014 ◽  
Vol 627 ◽  
pp. 153-157
Author(s):  
Nawadee Srisiriwat ◽  
Chananchai Wutthithanyawat
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Power Supply ◽  
Air Flow ◽  
Heating Zone ◽  
Velocity Control ◽  
Rectangular Duct ◽  
Air Velocity ◽  
Hot Air ◽  
Set Up

The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.

scholarly journals Heat Transfer Enhancement in Air Cooled Gas Turbine Blade Using

2021 ◽  
Vol 8 (3) ◽  
pp. 52-69
Author(s):  
Dr. Farhan Lafta Rashid Rashid ◽  
Dr. Haider Nadhom Azziz Azziz ◽  
Dr. Emad Qasem Hussein Hussein
Keyword(s):  
Temperature Distribution ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Air Temperature ◽  
Air Flow ◽  
Three Dimensions ◽  
Internal Diameter ◽  
Wall Surface ◽  
Gas Turbine Blade ◽  
Ansys Fluent

In this paper, an investigation of using corrugated passages instead of circular crosssection passages was achieved in conditions simulate the case in the gas turbine blade coolingusing ANSYS Fluent version (14.5) with Boundary conditions: inlet coolant air temperature of300 K with different air flow Reynolds numbers (191000, 286000 and 382000). Thesurrounding constant hot air temperatures was (1700 K). The numerical simulations was done bysolving the governing equations (Continuity, Reynolds Averaging Navier-stokes and Energyequation) using (k-ε) model in three dimensions by using the FLUENT version (14.5). Thepresent case was simulated by using corrugated passage of 3 m long, internal diameter of 0.3 m,0.01 m groove height and wall thickness of 0.01 m, was compared with circular cross sectionpipe for the same length, diameter and thickness. The temperature, velocity distributioncontours, cooling air temperature distribution, the inner wall surface temperature, and thermalperformance factor at the two passages centerline are presented in this paper. The coolant airtemperature at the corrugated passage centerline was higher than that for circular one by(12.3%), the temperature distribution for the inner wall surface for the corrugated passage islower than circular one by (4.88 %). The coolant air flow velocity seems to be accelerated anddecelerated through the corrugated passage, so it was shown that the thermal performance factoralong the corrugated passage is larger than 1, this is due to the fact that the corrugated wallscreate turbulent conditions and increasing thermal surface area, and thus increasing heat transfercoefficient than the circular case.

Required temperature distribution based on clothing insulation and metabolic rate survey in Japan

2019 ◽  
Vol 29 (6) ◽  
pp. 775-782
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe
Keyword(s):  
Physical Activity ◽  
Temperature Distribution ◽  
Metabolic Rate ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Metabolic Rates ◽  
Clothing Insulation ◽  
Office Environment ◽  
Temporal And Spatial ◽  
Temperature Side

In this study, the authors evaluated clothing insulation and changes in the metabolic rate of individuals in an office environment to determine thermal comfort. Clothing was evaluated using a questionnaire completed by 1306 workers in nine offices. The metabolic rates of 86 workers in three offices were measured using a physical activity meter. The distribution of the temperature at which a person in the room perceived a neutral thermal sensation was then calculated from the determined metabolic rates and clothing insulation values. The results demonstrate a noticeable difference between the average and most frequent values during the summer. Moreover, the required temperature distribution is not normal; rather, it is broad and skewed to the low-temperature side. Therefore, even if a thermally uniform environment is provided at the average required temperature by preventing temporal and spatial variations in the thermal environment, complaints of an unacceptably hot thermal environment are more likely to occur than complaints of an excessively cold thermal environment.

scholarly journals Thermophysiological Comfort of Surgeons and Patient in an Operating Room Based on PMV-PPD and PHS Indexes

2020 ◽  
Vol 10 (5) ◽  
pp. 1801 ◽  
Author(s):  
Radostina A. Angelova ◽  
Rositsa Velichkova
Keyword(s):  
At Risk ◽  
Relative Humidity ◽  
Operating Room ◽  
Air Temperature ◽  
Indoor Environment ◽  
Thermal Environment ◽  
Climatic Conditions ◽  
Clothing Insulation ◽  
Indoor Thermal Environment ◽  
Predicted Heat Strain

There are different actors in an operating room (OR), who have controversial requirements for the indoor thermal environment. While the patient is at risk of perioperative hypothermia, the surgeons are in a state of thermophysiological discomfort. The study presents an analysis of the thermophysiological comfort of both patient and surgeons in an OR. Surgical clothing ensembles with three values of clothing insulation are simulated. Different indoor environment conditions (air temperature and relative humidity) are tested. The analysis is based on the calculation of predicted mean vote and predicted percentage of dissatisfied (PMV-PPD) indexes and assessment of the climatic conditions categories. Discussion of the predicted heat strain is also presented. The simulated results and their analysis show considerable discrepancies between the thermophysiological comfort of the patient and the surgeons, even when dressed in a light protective ensemble, in the same indoor environment.

Combustion of Bio-Coke (Highly Densified Biomass Fuel) Block in High-Temperature Air Flow

2011 ◽  
Author(s):  
Hiroyuki Ito ◽  
Yuto Sakai ◽  
Tamio Ida ◽  
Yuji Nakamura ◽  
Osamu Fujita
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Mass Loss ◽  
Air Temperature ◽  
Degradation Rate ◽  
Loss Rate ◽  
Ignition Delay Time ◽  
Mass Loss Rate ◽  
Air Flow ◽  
Air Flow Rate

Bio-coke (BIC, highly densified biomass briquette), a newly developed biomass fuel as an alternative to coal coke which utilized in blast furnace, is employed in this study. This fuel is manufactured in highly compressed and moderate temperature conditions and has advantages in its versatility of biomass resources, high volumetric calorific value and high mechanical strength. Japanese knotweed is chosen as a biomass resource and is shaped into cylinder (48 mm in diameter and 85 mm in length). One of the most important characteristics of BIC is its high apparent density (1300 kg/m3; twice or more than that of an ordinary wood pellet). In the present study, combustion characteristics of a single BIC fuel in high temperature air flow (473–873 K, 550–750 NL/min.) are investigated. Air is preheated and blown to the bottom surface of the BIC. Ignition and subsequent combustion behavior are observed with monitoring gas temperature near the BIC, surface and inside the BIC temperature, and time dependent mass loss of the BIC is measured. In the case with low air temperature, low heat flux from the fuel surface leads to the broad temperature distribution inside the BIC accompanied by the increase in ignition delay time and, then, once ignition takes place degradation rate becomes larger than the case with high temperature air. On the other hand, mass loss rate for the case of solid surface combustion in the high temperature air does not depend on the air temperature but does depend on the air flow rate, which is a result of reduced degradation rate relating to narrow temperature distribution in depth caused by short ignition delay time. Consequently, it is suggested that the history of preheating, i.e. the preheated condition which is determined by air temperature and air flow rate, is an essential factor to determine the ignition mode in the early stage of BIC combustion and the mass burning velocity in the period of main combustion with flame. It is found that the mass loss rate of BIC in the gas-phase combustion period increases with decrease in supplied air temperature in this study.

scholarly journals Temperature distribution of a test specimen with high-speed heat air-flow passing through

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2527-2538 ◽  
Author(s):  
Kai Xiong ◽  
Yunhua Li ◽  
Sujun Dong
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Test Specimen ◽  
High Speed ◽  
Air Flow ◽  
Prediction Method ◽  
Average Temperature ◽  
Hot Air ◽  
Heat Transfer Theory ◽  
Good Agreement

In this paper, a solution method for the temperature distribution of rectangular test specimen with a high-speed heat air-flow passing through is proposed based on the heat transfer theory and numerical calculation, and the feasibility of temperature prediction method is validated. Firstly, the partial differential equations to describe the average temperature in the section of the hot air-flow and the specimen are established and the solving method using MATLAB solver is proposed. Then, based on heat transfer conduction equation and the average temperature, the temperature distribution at different point in each section is calculated. The comparison between numerical computation and experiment shows that two results are in good agreement, which verifies the correctness of the presented prediction method of the temperature distribution of the specimen.

scholarly journals Some Effects on the Temperature of the Mine Air at the Heading Face

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Van Quang NGUYEN ◽  
Van Thinh NGUYEN ◽  
Cao Khai NGUYEN ◽  
Van Chung PHAM
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Temperature Distribution ◽  
Air Temperature ◽  
Significant Influence ◽  
Thermal Environment ◽  
Simulation Method ◽  
Forced Ventilation ◽  
Ansys Cfx ◽  
Ventilation Method

Currently, with the increase in mining output leading to deeper mining levels, the volume ofheading face serving production has also increased. The thermal environment tends to worsen whendigging deep due to the geothermal's effect, which increases the air temperature at the heading face.According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. Toensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amountof air to ensure a favorable environment for workers. With the forced ventilation method, the duct positionis usually arranged on the side, and the distance from the duct mouth to the heading face is determined toensure that l < 6√s. In this study, a numerical simulation method by Ansys CFX software is applied tostudy the influence of several factors such as duct position, air temperature of duct, and roughnesscharacteristics of roadway on the temperature of the mine air at the heading face. The models are set upwith six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better thanmodels 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models havedifferent wind temperatures, and we can see the significant influence of the inlet air temperature of theduct on the thermal environment of the heading face. The results show that with the model T = 297.15K,the temperature value on the roadway length is guaranteed as specified < 303K. The result is a referencefor determining the duct position and cool for the high-temperature heading face.

scholarly journals Computation and measurement of air temperature distribution of an industrial melt blowing die

2014 ◽  
Vol 18 (5) ◽  
pp. 1705-1706
Author(s):  
Li-Li Wu ◽  
Dong-Hui Huang ◽  
Chuan Xu ◽  
Ting Chen
Keyword(s):  
Temperature Distribution ◽  
Flow Field ◽  
Temperature Measurement ◽  
Air Temperature ◽  
Measurement System ◽  
Air Flow ◽  
Melt Blowing ◽  
Air Temperatures ◽  
Slot Die ◽  
Temperature Measurement System

The air flow field of the dual slot die on an HDF-6D melt blowing non-woven equipment is computed numerically. A temperature measurement system is built to measure air temperatures. The computation results tally with the measured results proving the correctness of the computation. The results have great valuable significance in the actual melt blowing production.

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