Air Terminals Research Articles

Dynamic control of room air temperature for stratum ventilation based on heat removal efficiency: Method and experimental validations

Stratum ventilation can energy-efficiently provide quality indoor air and thermal comfort. The room air temperature in the occupied zone is a dominant parameter for thermal comfort. The non-uniform thermal environment of stratum ventilation challenges the dynamic control of the room air temperature. This study proposes a dynamic control method of the room air temperature for stratum ventilation based on heat removal efficiency. The proposed method requires inputs of only supply air temperature, supply airflow rate and exit air temperature, and can be readily employed by the building management system in practice. Dynamic experiments, with a wide variation range (i.e., from 24.5 °C to 30 °C), different variation rates (i.e., from 0 °C/min to 0.088 °C/min) and different variation trends (i.e., increase, decrease and steady) of the room air temperature, are conducted to validate the proposed method. The time interval of the dynamic experiments is 1 min. Furthermore, the effects of the cooling load and room occupancy are also analyzed to demonstrate the robustness of the proposed method. The differences between the predicted room air temperatures by the proposed method and measurements are no more than 0.33 °C, and the root mean square errors are no more than 0.18 °C. Compared with the conventional method, which assumes that the room air temperature equals to the exit air temperature at the air terminals, the proposed method improves the accuracy in the room air temperature prediction by 79.3%–93.3%. The proposed method can be applied to dynamically control the room air temperature to meet the requirement of thermal comfort.

Air Terminal Design using Photovoltaic Panels with Energy Conservation Optimization Approach

Today, excessive consumption of fossil fuels in architecture, especially air terminals and with the increase in the number of terminals along with population growth, the energy shortage crisis in the not-so-distant future in this high-use structure predicted. Therefore, the present study aims was designing an air terminal using photovoltaic panels with an energy efficiency optimization approach. The most important energy efficiency of the sun is its direct conversion to electricity. One of the systems for direct conversion of energy from radiation to electrical energy is the photovoltaic system. Advantages of using photovoltaic panels have led to the growing use of these plates at various scales. In addition, the use of photovoltaic panels as structural elements in architecture has created innovations in the building industry and has given a new meaning to the architecture. The use of photovoltaics in terminals is a smart method to bring contemporary architecture to a new concept in green architecture. Finally, we can say that photovoltaic module has a double function in the terminal; that is, photovoltaic module also replaces conventional building materials and they produce electricity. By replacing photovoltaics, cost of materials is deducted from the total cost of the building and the cost of the photovoltaic acquisition is partially offset. Such as the integration of photovoltaics with the roof which is the best way to get the maximum efficiency of the system in which the sun is perpendicular to it.

Smart Lightning Detection System for Smart-City Infrastructure Using Artificial Neural Network

Smart city infrastructure for lightning detection is one of the most important parameters for building protection. To get outcomes within a short frame of time having high accuracy Artificial Neural Network (ANN) is a better choice to be used. In this work, ANN is applied for automatic building detection process for the application of smart-city infrastructure, which has drawn very little attention of researchers due to unavailability of standard data sets and well-defined approach. Object detection follows the lightning strike pattern of the lightning flashes on different air terminals installed on multi-geometrical scaled structures. Initially, classification is carried out based on the object characteristics into different categories. In the proposed approach, the classification of buildings has been carried out on the basis of various states of terminals of different buildings. The proposed approach consists of four stages namely data collection, data labeling, classification; and performance evaluation. In the data collection stage, data is collected from different scaled buildings by switching on and off states of different terminals. In the data labeling stage, the data collected are given labels according to the types of buildings. The buildings have been categorized on the based on lightning air terminals installed on it. In the classification stage, ANN with different combinations of network training function, hidden layer transfer function output layer transfer function, number of neurons in the hidden layer and different number of epochs has been used to classify the buildings into their respective classes. Difference performance and accuracy was found for the evaluation of the work and the highest accuracy was found to be 92.6 followed by 85.27, 84.82, 82.81, 81.72, 80.18 and 79.75 for various architectures of the network. For the validation of the methodology, other types of classifiers have also been applied for the discrimination of different categories of the buildings.

Optimization of Passenger Screening Operations in Air Terminals

Abstract Airports today play an important economic role. As intermodal transport terminals, they have to channel important flows of passengers and goods. In recent decades, they have been the target of terrorist attacks and the place where all types of traffic pass. Consequently, they are faced with the dual objective of maximization of security system as well as maintenance of consistent quality and insurance of fluid traffic flow passengers coupled with the minimization of the expected amount of time a passenger spends in this system. In this article, we are interested in the evaluation of the system of control of passenger flows at boarding, whatever their subsequent path, through a probabilistic approach. The general purpose is to: Better organize the flow of passengers at boarding, taking into account the performance of the control system as a whole or the performance of the elements that make it up, including staff. Contribute to new knowledge about increasing efficiency and productivity at airports with regards to security system, by measuring and simulating the operations at an airport, and developing a strategy for improved resource utilization to improve productivity. After the establishment of a global evaluation model based on an undifferentiated serial treatment of passengers, we are interested in a two-stage control structure that highlights the interest of pre-filtering and organizing passengers in separate groups. This then leads to the formulation of optimization problems to improve the performance of the control system.”

Real scale experimental study for performance evaluation of unidirectional air diffuser perforated panels

Nowadays, there is an increasing emphasis on indoor air quality due to technological evolution and the fact that people spend most of the time in enclosed spaces. Also, energy efficiency is another related factor that gains more and more attention. Improving air distribution in an enclosure can lead to achieve these goals. This improvement can be done by adjustingthe air terminals position, theredimensions or the air diffuser perforations. The paper presents the study of 8 types of panels with different perforations shapes. The systems were characterized by flow, pressure loss and noise. Usualand special geometries were chosen, all having the same flowsurface. The perforated panels were mounted in a unidirectional air flow (UAF)diffuser, also called a laminar air flow (LAF)diffuser, that is placed in a real scale operating room (OR) in our laboratory.The purpose of this study is to determine whether changing the shape in the perforated panels can improve the technical parameters of the diffuser.

An EMD–SARIMA-Based Modeling Approach for Air Traffic Forecasting

The ever-increasing air traffic demand in China has brought huge pressure on the planning and management of, and investment in, air terminals as well as airline companies. In this context, accurate and adequate short-term air traffic forecasting is essential for the operations of those entities. In consideration of such a problem, a hybrid air traffic forecasting model based on empirical mode decomposition (EMD) and seasonal auto regressive integrated moving average (SARIMA) has been proposed in this paper. The model proposed decomposes the original time series into components at first, and models each component with the SARIMA forecasting model, then integrates all the models together to form the final combined forecast result. By using the monthly air cargo and passenger flow data from the years 2006 to 2014 available at the official website of the Civil Aviation Administration of China (CAAC), the effectiveness in forecasting of the model proposed has been demonstrated, and by a horizontal performance comparison between several other widely used forecasting models, the advantage of the proposed model has also been proved.

Manifestations composite element «movement» in the interior design of the terminal

This article was researched manifestation of direct and not direct traffic in the interior of the terminal in the world. Analysis 1000 images of interiors of modern air terminals on the topic of determination of display of motion as a composition element conducted. Three main features characterizing the movement: transforming (furnishings), compositional and dynamic (decoration), light (light, lighting effects). We derive a percentage of each kind of manifestation of the movement in the interior of the terminal. It was educed on the whole, that motion is used in the design of interiors of air terminals minimum on this stage, that not enough for the exposure of image reflecting the basic functional orientation of air terminal, are expectations of flight.

Air Flow Regimes and Thermal Comfort in Vehicle Cabin Considering Solar Radiation

Thermal comfort in vehicle cabin can affect drivers and passenger’s 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, especially because of individual differences regarding to physiological and psychological response, clothing insulation, activity, air temperature and air movement preference, etc. The main objective of this research is to study the air flow regimes and thermal comfort in vehicle cabin using computational fluid dynamics (CFD) software. For this purpose, the CFD software from ANSYS Inc., called FLUENT 17.2, is employed. In which the solar load model is embedded s2s (surface to surface) as a solar radiation model. The CFD modeling techniques solved the continuity, momentum and energy conservation equations in addition to standard k – e model equations for turbulence closure (The use K-epsilon turbulence mode was recommended as it had been widely tested and investigated in the seventies of last century). Meshing is processed around 4.0 million unstructured tetra-elements approximately. The performance of the air conditioning system is characterized by airflow regimes (air temperature, air velocity, relative humidity, PMV and PPD contours), the present work is focus on the effect of air terminal shape of Hvac system, two configurations are used case (1) and case (2). Case (1) is the existing design of air terminals of the Hvac system of the selected car (Skoda Superb), the air terminals are in rectangular shape. While case (2) are in circle shape

Reducing Dwell Time Related to Clearing and Forwarding of Export and Import Goods at Kolkata Sea and Air Ports

The article traces the opportunities for reducing the dwell time taken during clearing of export and import (EXIM) goods at Kolkata sea and air ports. As observed in the Government of India reports, the dwell time in Indian airports is considerably higher than that of global benchmarks. Drawing from the literature, we figured out that reduction in dwell time can reduce opportunity cost and lead to increased productivity and higher efficiency of the ports and air terminals. In the first phase of the study, using the Ishikawa Fishbone diagram, we have analyzed the reasons behind the higher dwelling time in Kolkata air and sea ports. In the second phase, following the value stream mapping process indicated by Barber and Tietje (2008), the current state map of the EXIM clearing process has been mapped and possible future state maps have been proposed for reduction in dwell time.

Measurement and Characterization of Low-Altitude Air-to-Ground MIMO Channels

To support the development of high-capacity air-to-ground links for range extension, measurements of the low-altitude air-to-ground channel were made at 915 MHz. Two transmit antennas were mounted on an unmanned aerial vehicle (UAV), which was flown in loops at an altitude of approximately 200 m above ground level. The received signals were recorded at each of eight antenna elements mounted on a van at locations outside and inside the flight loop. The analysis of the measurements shows that there are regions where the spatial diversity is significant, despite the sparse multipath environment, indicating spatial decorrelation at both the ground and air terminals. The variations in spatial correlation across the receiver array indicate the presence of nonplanar wavefronts produced by the signals' interaction with objects in the array near field, in particular the measurement vehicle. A similar effect is probable at the UAV, and it is expected that more significant near-field effects would arise on a more conventional air platform. These support significant reductions in outage probability at both receiver locations: With appropriate signaling strategies, an airborne platform could provide a viable relay or broadcast node for high-capacity communications using a multiple-input–multiple-output (MIMO) system.

Lightning surge analysis of Faraday cage using alternative transient program‐electromagnetic transients program

Lightning surge analysis of protective structures is significant for the design of system. However, simulation models are limited. In this study, a Faraday cage with four air terminals and 2 × 6 grounding rods built to protect a switchyard control building in a 380 kV substation is simulated in alternative transient program for the analysis of lightning surges. Distributed line modelling is used for cage conductors. Down conductors are represented by considering non-uniform variation of the conductor parameters. Current waveforms through the system and voltages at some critical points after a lightning stroke are computed. The traditional lightning parameters needed in structural protection such as lightning peak current, maximum current derivative, current rise time and current duration are determined. The effects of mesh size and some system parameters such as grounding resistance and lightning surge impedance are investigated.

Factors affecting the assessment of the selectivity of lightning impact for dimensioning the areas protected by air terminals

The factors affecting the selectivity of lightning discharges by air terminations are analyzed in the paper. For this aim the simulations of electric field distribution around the surface of conductive structures have been performed. The need for correction of normative methods for air termination dimensioning has been confirmed and the way for this correction depending on the lightning polarity has been proposed. Streszczenie. W artykule analizowane są czynniki mogące miec wplyw na wybiorczośc wyladowan piorunowych przez zwody. Dokonano symulacji rozkladu natezenia pola elektrycznego wokol przewodzących struktur naziemnych. Stwierdzono potrzebe i zaproponowano sposob korekty normatywnych metod wymiarowana stref chronionych w zalezności od biegunowości piorunow. (Czynniki wplywające na ocene selektywności uderzenia pioruna przy wymiarowaniu przestrzeni chronionych przez zwody)

An econometric evaluation of the management of large-scale transport infrastructure in Spain during the great recession: Lessons for infrastructure bubbles

This paper reviews the way that air, rail, and toll motorways infrastructure have evolved in Spain since the beginning of the century, when all these types of transport have been subjected to a far-reaching economic crisis. Investments made in infrastructure during this time will also be analyzed in relative terms and compared to other countries in the European Union, as will the various policies applied to each of these modes of transport. The methodology applied in this paper is of the bottom-up type, in the sense that a thorough univariate–uniequational analysis is performed before proceeding to more complex, multivariate models. We found that the policy to drop fare prices for the HSR (AVE) has had an almost 14% positive effect on the number of passengers per kilometer for HS and long-distance trains, but it has also had a negative effect of as much as 16.7% on the number of domestic air passengers. The increase in airport taxes has not affected any of the endogenous variables, or major public investments in air terminals and new HSR lines, except for the Madrid–Barcelona AVE and Barcelona's T1. Domestic air transport has been seen to be more sensitive to the economic cycle than the other modes of transport. This paper contains a set of results that justify the need to use full and accurate “economic modeling” in the planning and management of what is generally very costly transport infrastructure.

The Electric Field Effect on Angles of Copper-Type Down-Conductor

This paper is to study the effect of electric field on an angle variation of copper down-conductor due to voltage and current transient. Down-conductor which informs of numerous material, shape and dimension are mandatory for diverting the lightning current from air termination system to the grounding system in sheltered building. Hence, a numerical analysis method is applied emulating the comprehensible and particular model according to ordinarily used in the manufacturer’s datasheet specification. A rigorous assessment in term of electric fields was reviewed in comparison with the critical breakdown value of air for a crucial study. Later, a foremost angle is proposed for the installation of down-conductor in order to achieve a reliable protection system.

The new steel‐glass architecture of passenger service centres on expressways in Japan

AbstractNowadays, modern expressways worldwide are becoming very important arteries for the quick and safe transportation of people and goods. Service centres are located along these roads for the convenience of drivers and passengers. Those centres consist of buildings and other infrastructure elements and provide various services. Usually, buildings represent contemporary trends in architecture and structural engineering. Steel and glass are widely used. This is also the case in Japan but, simultaneously, adequate approaches are being made to respect the country’s own traditions as well. This paper is a continuation of the authors’ previous publications [1], [2], [3] devoted, respectively, to buildings, railway stations and air terminals.

Wireless sensor network based monitoring system for a large-scale indoor space: data process and supply air allocation optimization

Wireless sensor network (WSN) for building applications has been considered by many HVAC experts as an efficient tool to promote building energy efficiency and indoor thermal comfort. This paper, therefore, proposes a strategy of using WSN to monitor the temperature distribution in a large-scale indoor space, which aims to (i) improve the quality of the measurements transmitted by wireless signals, (ii) identify the temperature distribution pattern of the large-scale space, and (iii) optimize the allocation of supply air rated flow rate to multiple supply air terminals that serve the space according to the identified temperature distribution pattern. The developed strategy is illustrated by applying it to a real WSN test bed, installed in a typical large-scale space in Hong Kong. Results are presented and discussed, which shows that the phenomenon of temperature uneven distribution was commonly existent in a large-scale space and the developed strategy was able to efficiently improve the quality of measurements by WSN and improve the temperature homogeneity in the large-scale space.

Lightning Air Terminal Collection Volume Assessment: A New Technique and Device

For buildings, structures and facilities a Lightning Protection System (LPS) is very important. There are some components that affect the effectiveness of LPS. One of the components is the lightning air terminal. With reference to the facilities requiring lightning protection the position, the apparent height, and the angle of protection of lightning air terminals determines the collection volume (CV) of the protected area. The CV of direct strike lightning air terminals can change because of the facility is affected by natural disasters such as seismic tremor and flood. If such natural disasters do happen, there are possibilities that the facilities will not be fully protected from direct lightning strikes. The building and structure could be misalignment after the seismic tremor and flood related to earth movement. So for the safety of equipment and personnel, lightning protection system efficacy assurance is necessary. Therefore, there should be a technique and device to monitor the variation of collection volume afforded by every lightning air terminal on buildings and structures after the occurrence of a natural disaster. This paper presents a new technique as well as a new device to monitor the collection volume variation. A part of the device was obtained from a recycled moveable television antenna. This approach is not only practical, portable and cost effective but also incorporating the idea of environmental protection and recycling of used plastic materials.

The new steel‐glass architecture of air terminals in Japan

AbstractSteel‐and‐glass structures for buildings, railway stations and airports are currently representatives of modern infrastructure worldwide. The first two, characteristic of Japan, have been discussed in previous articles [1], [2]. In this paper the authors look at Japanese air terminals.

An experimental and numerical study on the effect of air terminal types on the performance of stratum ventilation

The purpose of this paper is to investigate the effect of air terminal types on the design and performance of stratum ventilation. Four types of air terminals, including circular diffusers, square diffusers, perforated diffusers and double deflection grilles were studied by experimental and numerical methods. Human subject tests of thermal sensations and comfort were conducted under various experimental conditions. The performance of stratum ventilation was evaluated by six indicators: airflow pattern, temperature distribution, air diffusion performance index, thermal sensation and comfort feedback, local mean age of air and CO2 concentration. The results indicate that air terminal type has a significant effect on airflow pattern. Good air diffusion performances were achieved with four types of diffusers. More than 80% subjects felt thermally comfortable with circular and perforated diffusers. In terms of air quality, the local mean age of air for the circular diffuser case was the oldest, while the CO2 concentration in the breathing zone was the second lowest and the most uniform for this case. Thus, the circular diffuser can be a better choice for stratum ventilation.

An investigation into the performance of fabric diffusers used in stratum ventilation

Fabric terminals made of polymer were found to potentially provide a clean, healthy and comfortable indoor environment. In this paper, the performance of fabric diffusers under stratum ventilation is investigated. A total of nine cases, eight of which with fabric diffusers and the other one with a double deflection grille, are conducted in an experimental classroom. The performance of fabric diffusers under stratum ventilation is studied by analyzing the velocity and temperature distributions, the effective draft temperature, the air diffusion performance index and the thermal sensation and comfort feedback. The experimental results show that fabric diffusers perform better under a higher airflow rate. Compared with double deflection grilles, fabric diffusers were able to provide a relatively uniform velocity and temperature distribution for most of the areas in a room and a more comfortable thermal environment. It performs better in air diffusion than double deflection grilles. Therefore, fabric diffusers can be used as air terminals for stratum ventilation.