Interior Heat Research Articles

MHD conjugate mixed convection along with internal heat generation and Joule heating in a closed/open cavity with rotating solid cylinder

PurposeThis study aims to investigate magnetohydrodynamic (MHD) conjugate pure mixed convection considering interior heat production and resistive heating inside a square closed/open cavity featuring a rotating cylinder for aiding (clockwise) and opposing (counterclockwise) flow configurations. Moreover, the impacts of altering cylinder size and conductivity on the system’s overall performance to determine optimum conditions are examined in this investigation.Design/methodology/approachThe closed chamber is differentially heated by keeping high and low temperatures at the vertical boundaries. In contrast, the open cavity has a heated left wall and an open right boundary. The Galerkin finite element method is used to solve the Navier–Stokes and the thermal energy equations, which construct the present study’s mathematical framework. Numerical simulations are conducted for the specified ranges of several controlling parameters: Reynolds (31.62 ≤ Re ≤ 1000), Grashof (103 ≤ Gr ≤ 106) and Hartmann numbers (0 ≤ Ha ≤ 31.62), and volumetric heat generation coefficient (Δ = 0, 3).FindingsWhen Gr, Re and Ha simultaneously increase, the average Nusselt number along the warmed boundary rises accordingly. Conversely, interior heat production lowers heat transmission within the computational domain, which is also monitored regarding mean fluid temperature, overall entropy production and thermal performance criterion. Finally, the open cavity confirms better thermal performance than the closed cavity.Originality/valueComprehending the impacts of the magnetic field, Joule heating, internal heat generation and enclosed or open boundary on pure MHD combined free-forced convective flow offers valuable understandings of temperature fluctuations, velocity propagations, heat transport and irretrievable energy loss in numerous engineering applications.

Magnetohydrodynamic convection in a heat-generating ferrofluid within a corrugated cavity containing a rotating cylinder

This study introduces a novel approach by combining magnetohydrodynamic flow with Joule heating effects to investigate the conjugate mixed convective flow of ferrofluid in a non-homogenously warmed wavy-walled squared-shaped chamber with a spinning cylindrical object positioned at the center of the chamber. The current study seeks to maximize heat transmission effectiveness by scrutinizing optimum system attributes and conducting entropy production analysis. Numerical solutions are achieved by employing the Galerkin finite element weighted residual approach to solve the two-dimensional Navier–Stokes and heat energy equations representing the mathematical model. The parametric alterations encompass Grashof (103 ≤ Gr ≤ 106), Reynolds (31.62 ≤ Re ≤ 1000), and Hartmann (5.623 ≤ Ha ≤ 31.623) numbers, volumetric heat generation coefficient (0 ≤ Δ ≤ 10), thermal conductivity ratio (K = 20.07, 95.14), corrugation frequency (6.5 ≤ f ≤ 8.5), dimensionless corrugation amplitude (0.02 ≤ A ≤ 0.04), and dimensionless cylinder diameter (0.3 ≤ D ≤ 0.5). The study assesses the thermal characteristics of a heat source and the entropy generated within the computational domain while considering varying corrugation frequency and amplitude, cylinder diameter, thermal conductivity, strength of magnetism, and heat generation. The findings are quantitatively showcased through the Nusselt number of the hot wall, mean fluid temperature, overall entropy production, and thermal performance criterion (TPC) across the domain. After extensive analysis, it is evident that minimum cylinder diameter (= 0.3), corrugation frequency (= 6.5), and amplitude (= 0.02) while the maximum thermal conductivity ratio (= 95.14) ensure optimal system performance. Surprisingly, incorporating interior heat production diminishes thermal performance significantly while increasing TPC. Understanding the impacts of the magnetic field, Joule heating, and interior heat production on convective flow offers key perceptions into temperature variation, heat transport, velocity profile, and irreversible energy loss in numerous engineering applications.

Effects of internal heat production and Joule heating on MHD conjugate mixed convection and entropy production inside a thermally non-homogeneous cooling system

The current investigation explores MHD combined free-forced convection and entropy generation within a square enclosure (e.g., a nuclear reactor heat removal system) incorporating resistive heating and interior heat production. The cavity features a centrally positioned rotating cylinder, with the leftmost edge kept at a greater temperature than the rightmost boundary. The upper and lower boundaries of the enclosure are thermally insulated throughout the analysis. The solid cylinder rotates clockwise or counterclockwise, generating an aiding or opposing flow configuration. The Galerkin finite element approach solves the two-dimensional Navier-Strokes and thermal energy equations. Four different cases are analyzed through numerical simulations within predetermined ranges of Grashof (103 ≤ Gr ≤ 105), Reynolds (31.623 ≤ Re ≤ 316.23), and Richardson (0.1 ≤ Ri ≤ 10) numbers to analyze conjugate laminar mixed convective flow. Besides, Hartmann (0 ≤ Ha ≤ 17.783) and Stuart (0 ≤ N ≤ 3.162) numbers are varied to address the change in the magnetic field’s intensity considering resistive heating. Finally, the volumetric internal heat production factor (0 ≤ Δ ≤ 3) is considered to account for internal heat generation. This study’s comprehensive quantitative findings encompass the system’s thermal performance, leading to significant conclusions in their respective cases. It is observed that elevating Ri while decreasing Ha or increasing both Ri and N leads to enhanced heat transfer and a reduced average fluid temperature. In contrast, during pure mixed convective flow, Nu rises with simultaneous increments in Gr and Re and decreases in N. Conversely, internal heat production results in lower heat transfer and notable increases in entropy generation and thermal performance criterion. Significantly, during pure mixed convection (Ri = 1) with an aiding flow configuration, the introduction of internal heat generation results in a 36.47 % degradation in heat transport at constant Gr, Re, and N. However, under identical conditions (fixed Gr, Re, and N) and Δ = 0, the aiding flow exhibits 26.91 % better thermal performance than the opposing flow.

Research progress of Chinese herbal medicines and classic prescriptions in the treatment of COPD based on the TCM theory and medicinal characteristics

Abstract Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with a complex pathogenesis, which causes the lack of precise and personalized prevention, control, and treatment approaches in clinical practice. Traditional Chinese medicine (TCM) with multiple components acting on multiple targets plays a role in the prevention and treatment of COPD. After evaluating the treatment of cough, dyspnea, and lung distension based on syndrome differentiation in TCM, we summarized the commonly used TCM preparations for treating COPD. These preparations are mainly composed of medicines for clearing interior heat and releasing exterior, tonifying, activating blood and resolving stasis, resolving phlegm, relieving cough and breathlessness, and regulating Qi movement. Because all of them contain a variety of active ingredients such as flavonoids, terpenoids, and phenols, we analyzed the mechanisms of the classic prescriptions alone or in combination with other medicines or therapeutic methods. These mechanisms involve counteracting inflammation, oxidative stress, and fibrosis, inhibiting apoptosis, alleviating airway remodeling, and enhancing immunity. Meantime, we summarized the existing problems in the treatment of COPD by TCM. This review provides a scientific basis for the research and treatment of COPD in the future.

Evaluation of energy-saving potential and indoor thermal environment of passive solar houses in various heating climate regions of China

ABSTRACT Passive solar houses comprise crucial strategies of reducing heating and cooling energy for buildings, which have been extensively used in plenty of nations. This study develops a study on indoor thermal environment, the energy-saving performance and natural lighting in different heating climate regions (represented by Lhasa, Xining and Urumqi). An attached-sunspace solar house integrated with phase change material floors is also proposed to ameliorate indoor thermal comfort and simultaneously diminish the heating energy consumption. In addition, the dominant factors analysis of building envelope affecting building energy consumption are sensitively studied. Moreover, the influence of the depth of sunspace and the intensities of internal heat gain on indoor thermal conditions and heating energy consumption are further analyzed. The results indicate that among the three types of solar houses, the passive solar sunspace offers the most stable indoor temperature and Trombe-wall solar houses and attached-sunspace solar houses have striking energy-saving advantages compared with the traditional houses. And the annual power consumption of 695.1 kWh, 427.4 kWh and 688.8 kWh in Lhasa, Xining and Urumqi can be saved in view of natural lighting respectively. Additionally, the whole natural temperature of attached-sunspace solar house is on the rise apparently when the PCM floors are embedded in the house and the energy saving fraction of these three regions is 81.9% for Lhasa, 68.8% for Xining, 55.7% for Urumqi respectively with the integration of phase change floors. The sensitivity analysis of key parameters impacting building energy consumption from high to low are the heat transfer coefficient of external wall, the ratio of window to wall, air tightness, the heat transfer coefficient of external window, and the heat transfer coefficient of roof. The depth of 1.2 m for sunspace is recommended as the optimal choice. Indoor natural temperature is on the rise as intensities of internal heat gain increase. The same downward trend for the main bedroom and the whole building is displayed with the increasing interior heat sources in terms of annual heating load.

A computational fluid dynamics (CFD) modeling in a new design of closed greenhouse

Closed greenhouses are crucial buildings for agriculture in controlled environments because they offer the best growing conditions for crops and shield them from outside influences. Researchers can now better optimize design parameters for increased crop output and energy efficiency by simulating airflow and temperature distribution inside closed greenhouses with the use of computational fluid dynamics (CFD) modeling. We examine the temperature distribution and airflow patterns inside the greenhouse under various environmental conditions using CFD simulations. Our findings show that, in comparison to traditional greenhouse constructions, the novel design greatly improves temperature uniformity and lowers energy use. Moreover, the greenhouse's thermal insulation design minimizes heat loss during the colder months, enhancing energy efficiency overall. We offer important insights into how design changes affect airflow dynamics and thermal performance in enclosed greenhouses by utilizing CFD modeling. Our research highlights how effective CFD modeling can be in maximizing crop yields and achieving sustainable agricultural practices through greenhouse design optimization. The integration of novel design components for improved energy efficiency and crop yield is a feasible outcome of this research, which advances the field of closed greenhouse technology overall. The research highlights the value of using CFD modeling to inform the design of next-generation closed greenhouse systems and has important ramifications for sustainable agriculture methods and greenhouse management techniques. The goals were to assess how well various heating/cooling systems maintained the ideal environmental conditions for plant growth. A verified CFD model was used to run the simulations, which took into account a number of variables including the shape of the greenhouse, the outside environment, and the interior heat sources. Important discoveries include understanding temperature gradients, airflow patterns, and possible areas for environmental management enhancement are presented in this paper. Results showed that the species mass transfer of vapor (H2o) will vary over time.

MHD Convection with Joule Heating and Internal Heat Generation in a Two‐Layer Discretely Heated Chamber Partly Filled with Porous Medium

The present research presents an innovative approach by integrating magnetohydrodynamic (MHD) flow with resistive heating, integrating a partly permeable layer and interior heat production to scrutinize natural convective flow within a square domain. It also examines both straight and wavy interfaces between the porous and fluid domains. Engaging the Galerkin finite element‐based weighted residual approach, numerical solutions are obtained by unraveling the two‐dimensional Navier–Stokes and thermal energy equations for pure fluid and fluid‐saturated porous domains. The parametric variations include Rayleigh numbers (Ra), porous layer thickness (H), corrugation frequency (f), corrugation amplitude (A), Hartmann number (Ha), and the heat production coefficient (∆). This study assesses the thermal effectiveness of a discrete thermal source, considering variations in porous layer thickness, corrugation frequency and amplitude, magnetic force intensity, and heat production impacts. The discoveries are demonstrated resolvably through the Nusselt number along the warmed edge, thermal performance criterion, and a qualitative portrayal of flow and thermal fields. After extensive analysis, it becomes apparent that reduced thickness of the porous layer, corrugation frequency, and amplitude enhance thermal performance. However, diminished porous layer thickness and corrugation frequency contribute to higher thermal performance criterion (TPC), whereas decreased corrugation amplitude results in a lower TPC. Specifically, the lowest values of H, A, and f result in 11.5%, 0.6%, and 0.1% higher thermal performance, respectively, compared to their highest values. Furthermore, a straight fluid‐saturated porous to the pure fluid domain interface, as opposed to a wavy interface at the highest H, A, and f values, offers a 0.7% improvement in thermal performance.

Impacts of Stratospheric Ozone Recovery on Southern Ocean Temperature and Heat Budget

AbstractThe impacts of stratospheric ozone recovery on Southern Ocean surface and interior temperature, heat content, heat uptake, and heat transport are investigated by contrasting two ensemble chemistry‐climate model simulations in 2005–2099: one with fixed ozone depleting substances (ODSs) and another with decreasing ODSs. In our simulations ozone recovery significantly affects Southern Ocean temperature, with large latitudinal and vertical variations. Ozone recovery causes a dipole change of the full‐depth ocean heat content (OHC) with an increase south of 60°S and a decrease between 45°S and 60°S. Integrated over latitudes south of 40°S, OHC decreases in response to ozone recovery. This ocean heat loss is shown to be driven by weakened poleward ocean heat transport (OHT) across 40°S, which is partly canceled by enhanced heat uptake. The weakening of poleward OHT into the Southern Ocean is caused by the ozone‐induced equatorward shift of the meridional overturning circulation.

Cooling performance of thermal management system for lithium-ion batteries using two types of cold plate: Experiment and MATLAB/Simulink-Simscape simulation

The thermal management system for lithium-ion batteries (LIBs) was investigated to improve the operating performance of LIBs. Experiments with two battery packs that integrate two different types of cold plates, Type I and Type II, were conducted to compare the cooling efficiencies of the battery thermal management system (BTMS). The interior heat generation of the battery modules was analyzed. Because of safety concerns, the battery pack in the experiment was replaced by heaters. A comparative experiment with a cell and heater was conducted under the same parameter conditions to compare the heating properties. The MATLAB/Simulink - Simscape toolbox (version R2020b) was used to simulate the thermal characteristics of a cylindrical cell and a battery pack. The thermal resistance was analyzed to investigate the cooling efficiency of the cold plates. As the results, the heater produced 10% higher temperature than the Li-ion cell under same conditions. In Type I, the thermal resistance decreased with an increase in the C-rates, whereas in Type II, it remained constant at 0.001. The simulation results were verified accurately through comparison with experimental results. Both experimental and simulation results show cold plate Type II has outstanding cooling performance than Type I.

Cooling strategy for punches in hot compound extrusion of critical train components

Failure of critical train components (CTCs) affects normal train operation or can cause serious accidents, resulting in economic losses. The design and manufacture of large, complex and precise punches is critical for the manufacture of CTCs. During extrusion, punches are at high temperature, which has a negative influence on the processing accuracy and reliability of CTCs. Hot compound deformation due to a long punch stroke reduces the life of punches, increasing manufacturing costs. Therefore, ensuring the timely cooling of punches is important for machining accuracy. A cooling strategy for punches under hot compound extrusion of CTCs is proposed. Based on computer-aided engineering technology, the cooling process of a punch was numerically simulated. Then, the design of an auxiliary mould was optimised and the process parameters were adjusted. The theoretical temperature rise of the punch was calculated and a formula for temperature rise and cooling of the punch obtained. According to the forced convective heat transfer of cooling water, the convective heat transfer coefficients on the surface of the cooling pipe were calculated. The interior and external heat dissipation of the punch were simulated using finite elements and the production beat and compound extrusion parameters were calculated. Interior circulation cooling equipment was then designed. Variations in the temperature field distribution were obtained after punch extrusion and heat dissipation using infrared temperature measuring equipment. The experimental and theoretical results agreed.

Properties of new exotic traditional Chinese medicinal Vernonia amygdalina leaves:a literature research

The leaves of Vernonia amygdalina Delile of the family Asteraceae(also known as "bitter leaf"), rich in biological activities, are used as both medicine and food for a long time in West tropical Africa. They have been introduced into Southeast Asia and Fujian and Guangdong provinces of China in recent years. However, little is known about the properties of the plant in traditional Chinese medicine(TCM), which limits its combination with other Chinese medicinal herbs. In this study, 473 articles on V. amygdalina leaves were selected from PubMed, Web of Science, CNKI, Wanfang Data and VIP to summarize their components, pharmacological effects and clinical research. V. amygdalina leaves presented anti-microbial, hypoglycemic, anti-hypertensive, lipid-lowering, anti-tumor, anti-inflammatory, antioxidant, and other pharmacological effects. On the basis of the theory of TCM properties, the leaves were inferred to be cold in property and bitter and sweet in flavor, acting on spleen, liver, stomach and large intestine and with the functions of clearing heat, drying dampness, purging fire, removing toxin, killing insects and preventing attack of malaria. They can be used to treat dampness-heat diarrhea, interior heat and diabetes, malaria, insect accumulation and eczema(5-10 g dry leaves by decoction per day and an appropriate amount of crushed fresh leaves applying to the affected area for external use). Due to the lack of TCM properties, V. amygdalina leaves are rarely used medicinally in China. The determination of medicinal properties of the leaves is conducive to the introduction of new exotic medicinal herbs and the development of new TCM resources, which facilitated further clinical application and research and development of Chinese medicinal herbs.

A Morphological and Spatial Analysis of Volcanoes on Venus

AbstractVenus is home to many thousands of volcanic landforms that range in size from much less than 5 km to well over 100 km in diameter. Volcanism is clearly a major, widespread process on Venus, and is a principal expression of the planet's secular loss of interior heat. Without sufficient in situ data to clearly determine its internal structure, we can use the morphological and spatial properties of volcanoes across the planet to help place constraints on our understanding of the volcanic characteristics and history of Venus. With the Magellan synthetic‐aperture radar full‐resolution radar map left‐ and right‐look global mosaics at 75 m‐per‐pixel resolution, we developed a global catalog of volcanoes on Venus that contains ∼85,000 edifices, ∼99% of which are <5 km in diameter. We find that Venus hosts far more volcanoes than previously mapped, and that although they are distributed across virtually the entire planet, size–frequency distribution analysis reveals a relative lack of edifices in the 20–100 km diameter range, which could be related to magma availability and eruption rate. Through spatial density analysis of volcanoes alongside assessments of geophysical data sets and proximal tectonic and volcanic structures, we report on the morphological and spatial patterns of volcanism on Venus to help gain new insights into the planet's geological evolution.

Uncertainty method and sensitivity analysis for assessment of energy consumption of underground metro station

An accurate calculation of energy consumption is a precondition for energy underground metro station design, which determines the amount of energy geostructure. This study develops a simplified deterministic method for the underground metro station energy performance that accounts for weather and interior heat gain uncertainty. A Monte Carlo technique with Latin hypercube sampling is then employed to confirm the probability distributions of the peak load, average yearly load and annual energy demand, and compared to deterministic method to improve the design robustness. The sensitivities of 14 input variables with respect to the underground metro station energy performance are discussed through three sensitivity methods. The simplified deterministic method is more accurate than the DeST and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) in describing the fluctuation of the underground metro station energy performance. The uncertainty distribution of energy performance is advantageous to the system design, considering both safety and economy. Moreover, a comparison with the deterministic method is performed to determine the reasonability of the safety factor 1.2, which is usually used in practical programs. The peak load is dominated by outdoor parameters, while there are no control parameters for the average yearly load or annual energy demand.

Distribution characteristics of traditional Chinese medicine syndromes in 4 367 adult influenza patients: a Meta-analysis

To systematically evaluate the distribution characteristics of traditional Chinese medicine (TCM) syndromes in adult influenza patients and to provide a basis for the TCM syndrome differentiation of influenza. The CNKI, CBM, Wanfang, VIP, PubMed, Embase, Cochrane Library databases were searched to collect cross-sectional studies on the distribution pattern of TCM syndromes in adult patients with influenza. The risk of bias assessment tool for cross-sectional studies developed by the Joanna Briggs Institute (JBI) evidence-based health care center was used to evaluate the literature quality, and the Stata 15.1 software was used to conduct a Meta-analysis of the pooled effect sizes of the included studies. A total of 11 studies with 4 367 influenza patients were included. Quality assessment results of JBI showed that the risk bias was higher in the sample size calculation, and the description of sampling modalities and response rate was unclear. There were 17 influenza syndromes after specification, and a single group rate Meta-analysis was performed of the syndromes with ≥ 50 incident cases showed that there were 9 syndromes with an incidence ≥ 10% and statistical significance, the top 5 syndromes were syndrome of wind and heat invading the defense [n = 1 583, RATE = 34.3%, 95% confidence interval (95%CI) was 22.2%-46.3%], syndrome of exterior cold and interior heat (n = 1 122, RATE = 36.1%, 95%CI was 21.2%-51.1%), syndrome of wind-cold fettering the exterior (n = 860, RATE = 19.4%, 95%CI was 10.7%-28.0%), syndrome of heat and toxin in the lung (n = 217, RATE = 17.1%, 95%CI was 9.1%-25.0%), and syndrome of disease involving both defense phase and qi phase (n = 184, RATE = 38.8%, 95%CI was 14.2%-63.5%). The results of the subgroup analysis in different geographical regions showed that the frequency of distribution of syndrome of wind and heat invading the defense and heat and toxin in the lung was higher in the South (RATE: 36.5%, 18.6%) than in the North (RATE: 30.9%, 15.4%), and the frequency of distribution of syndrome of wind-cold fettering the exterior and exterior cold and interior heat in the North (RATE: 23.8%, 40.1%) was higher than that in the South (RATE: 15.7%, 32.3%). There are 9 common TCM syndromes of influenza, including wind and heat invading the defense syndrome, exterior cold and interior heat syndrome, wind-cold fettering the exterior syndrome, heat and toxin in the lung syndrome, disease involving both defense phase and qi phase syndrome, wind and heat complicated by dampnessinvading the surface syndrome, wind and cold complicated by dampnessinvading the surface syndrome, defense phase syndrome and dampness and heatinvading the surface syndrome, which can provide a reference for the TCM syndrome differentiation and treatment of influenza.

The Effect of Interior Heat Flux on the Atmospheric Circulation of Hot and Ultra-hot Jupiters

Many hot and ultra-hot Jupiters have inflated radii, implying that their interiors retain significant entropy from formation. These hot interiors lead to an enhanced internal heat flux that impinges upon the atmosphere from below. In this work, we study the effect of this hot interior on the atmospheric circulation and thermal structure of hot and ultra-hot Jupiters. To do so, we incorporate the population-level predictions from evolutionary models of hot and ultra-hot Jupiters as input for a suite of general circulation models (GCMs) of their atmospheric circulation with varying semimajor axis and surface gravity. We conduct simulations with and without a hot interior, and find that there are significant local differences in temperature of up to hundreds of Kelvin and in wind speeds of hundreds of meters per second or more across the observable atmosphere. These differences persist throughout the parameter regime studied, and are dependent on surface gravity through the impact on photosphere pressure. These results imply that the internal evolution and atmospheric thermal structure and dynamics of hot and ultra-hot Jupiters are coupled. As a result, a joint approach including both evolutionary models and GCMs may be required to make robust predictions for the atmospheric circulation of hot and ultra-hot Jupiters.

Local room‐side heat transfer of an office room with different heating strategies

AbstractThe room‐side heat transfer of a building is essential for calculating and simulating heat loss through radiation and convection in interior spaces, and also for preventing mould growth and condensation. By means of Computational Fluid Dynamics (CFD) simulations, this study investigates the effect of floor heating, mixing ventilation, furniture, room geometry, and their combinations on the interior heat transfer coefficient (HTC) of a typical office room. The results show an inhomogeneous distribution of the HTC on the exterior walls. HTC values are generally below the German standardised value for thermal protection, which means an overestimation of the heat loss when the standardised value is applied. However, compared to the standardised value for preventing mould growth, the minimum surface‐averaged HTC behind closets is 63 % lower, potentially leading to mould growth and condensation.

Study of Thermal Comfort In Cafes In Bandung

The purpose of this study was to determine the study of thermal comfort in cafes in Bandung. Indonesia is a country with a tropical climate because its geographical position is on the equator. According to data from the Meteorology, Climatology and Geophysics Agency, the average humidity and temperature in 2020 is 27.30C. The method used to analyze the object of this study is a quantitative method with the formula of Thermal Equilibrium, quantitative research is defined as research based on empirical experience that collects data in the form of numbers that can be calculated and in numerical form. This research was conducted with a quantitative approach by performing calculations using the heat balance method to determine the heat in the 3 study objects and what factors most influence the cooling load in the 3 study objects. Human comfort at Noah's Barn Coffeenery, Amber Field Coffee cannot be separated from the thermal comfort factor. Based on the calculation of the thermal balance in the three cafes, more than 50% of the heat in the room comes from interior heat sources, especially electronic equipment and lighting and humans are the biggest heat contributor in the cafe dining area. Each cafe has a different heat source, therefore, each room has a different solution. The heat in Naoh's Barn Coffeenery is 25.2412504 kW

Study of Thermal Comfort In Cafes In Bandung

The purpose of this study was to determine the study of thermal comfort in cafes in Bandung. Indonesia is a country with a tropical climate because its geographical position is on the equator. According to data from the Meteorology, Climatology and Geophysics Agency, the average humidity and temperature in 2020 is 27.30C. The method used to analyze the object of this study is a quantitative method with the formula of Thermal Equilibrium, quantitative research is defined as research based on empirical experience that collects data in the form of numbers that can be calculated and in numerical form. This research was conducted with a quantitative approach by performing calculations using the heat balance method to determine the heat in the 3 study objects and what factors most influence the cooling load in the 3 study objects. Human comfort at Noah's Barn Coffeenery, Amber Field Coffee cannot be separated from the thermal comfort factor. Based on the calculation of the thermal balance in the three cafes, more than 50% of the heat in the room comes from interior heat sources, especially electronic equipment and lighting and humans are the biggest heat contributor in the cafe dining area. Each cafe has a different heat source, therefore, each room has a different solution. The heat in Naoh's Barn Coffeenery is 25.2412504 kW

Flow and heat transfer studies of multijet impingement cooling for different configurations: A review

AbstractIncreasing the gas turbine engine's turbine intake temperature has long been a potential strategy for increasing the specific work output of the engine. However, the melting temperature of the turbine blades and vane material limits the maximum intake temperature. As a result, internal and external cooling techniques are commonly used to maintain the vane material in a safe condition. This study provided an overview of internal impingement cooling to highlight the significance of geometrical variations, such as flat plate, curve plate, and actual vanes. It was observed that flat and curved plate impingement heat transfer studies were reported extensively, whereas limited studies were found on the conjugate effects on airfoil surfaces. The importance of conjugate heat transfer studies and their impact has recently been described in the literature. In most of the literature, a wide range of instruments, such as Laser Doppler Velocimeter, Particle Image Velocimeter, liquid crystal sheets, and so forth, were used for experimental investigations. According to most studies, the local value of internal surface temperature and heat transfer coefficient are vital factors of local flow behavior. Jet‐to‐jet spacing, jet‐to‐plate spacing, jet hole diameter, and jet Reynolds numbers played a crucial role in both numerical and experimental analyses. Different geometric variations strongly influence flow behavior. Therefore, the usual method for determining interior temperature distributions and heat transfer coefficients by considering generalized geometries like the flat and curved plate may not produce accurate conjugate solutions. Most of the computational studies on the flat and curved plate indicate the usage of κ−ω shear stress transport and κ–ε realizable model to predict the heat transfer coefficient.

Numerical investigation of heat transfer and fluid motion in air inflatable textiles: Effect of thickness, surface emissivity and ambient temperature

Air inflatable textile has attracted increasing attention due to the advantage of light, cheap, environmentally friendly and low thermal conductivity. While its thermal insulation is still not yet well understood since the complex interior heat and mass transfer under various thickness and ambient conditions. In this work, a three-dimensional model was developed to investigate the fluid motion and heat transfer in both air inflatable and fiber-filled textiles. The coupled conduction, convection and radiation were modelled by CFD approach. The experimental and numerical results were compared to verify the proposed model. Good agreements were found with the average difference in surface temperature and heat flux less than 2.54% and 9.95%, respectively. Then the effect of various parameters including thickness, surface emissivity and ambient temperature on heat flux, thermal resistance and fluid flow behavior was further analyzed. The simulated interior velocity and temperature distribution suggested that the higher thickness (≥10 mm) was not favorable for better thermal insulation when the air was adopted as thermal insulation layer. Because more available space for air movement would accelerate thermal convection and result in the deteriorated thermal insulation. In addition, inner surface layer with lower emissivity could effectively suppress the thermal radiation in air inflatable textiles and was beneficial to increase the thermal insulation. Besides, the thermal insulation of fiber-filled textile was nearly unaffected when lower ambient temperature was applied, while that of air inflatable textiles significantly decreased due to the aggravated convective heat and flow transfer under large temperature difference.