Tower Type Research Articles

Dynamic Response Of Tower Structures

The present study focuses on the tower type structures response to the dynamic loads. The study analyzes the possible mode shapes regarding to tower structure. The estimation of mode shapes and their dependence from structural changes was made for an existing tower structure. To get an acceptable tower’s vibration level and avoid possibility of resonance effect from usual serviceability loads it was evaluated options to change natural frequencies of the structure. It is performed existing 36m high sightseeing tower dynamic analysis and proposed potential solutions to increase critical natural frequencies of the structure. In this study to obtain dynamic parameters of the sightseeing tower structure have been used finite element models and calculation techniques.

Seismic vulnerability and failure modes simulation of ancient masonry towers by validated virtual finite element models

Seismic protection of ancient masonry towers is a topic of great concern among the scientific community. A methodology for the seismic vulnerability assessment of all types of towers and slender unreinforced masonry structures (e.g., light houses and minarets) is presented. The approach is developed by four validated 3D FEM models representative of European towers. The models are subjected to linear elastic investigations to establish load carrying capacity and dynamic properties for validation against similar towers. Seismic simulations are developed through intensive nonlinear static pushover analyses. From the assessments, the failure modes and overall seismic response of the towers are obtained. Low tensile strength of masonry and large openings at belfries have significant influence on the seismic behavior, resulting in a quasi-brittle failure. All the towers presented an imminent high vulnerability to seismic actions. The few investigations reported in literature on the seismic behavior of towers are focused on in-plane behavior, disregarding out-of-plane behavior and toe crushing, both aspects are investigated in this paper. The more flexible towers are close to present toe crushing in both planes. The failure mechanisms are validated with reported post-earthquake observations on real damaged towers.

Numerical Analysis on the Performance of Vertical Axis Wind Turbine Affected by the Configuration of the Wind Power Tower

A wind power tower can be applied to enhance the output power on the vertical axis wind turbine (VAWT). Usually, the wind power tower can be constructed as a multi-story building to increase the frontal area of wind stream. Hence, multiple sets of the VAWT can be installed within the wind power tower, and also they can be operated at high elevation. Many different types of wind power tower can be used in the field. In this study, a wind power tower with circular column shape was applied, and the VAWT was installed at the center of the wind power tower. Seven guide walls were used as a strut between the floors of the wind power tower. These guide walls were utilized not only to increase the wind velocity within the wind power tower but also to adjust the wind direction for making better working condition on the VAWT. Hence, some important design variables, such as the distance between the wind turbine and the guide wall, the outer diameter of the wind power tower, the direction of the guide wall against the wind direction, were studied to find optimum dimension by the numerical analysis obtained at the transient state. The results showed that the output power of the VAWT obtained using the wind power tower was increased compared to them obtained without the wind power tower. In addition, they showed that the increased output power on the wind turbine was greatly depended on the dimension of the guide wall.

Improvement in Solar Chimney Power Generation by Using a Diffuser Tower

The solar chimney prototype, operated in Spain from 1982 to 1989, verified the concept of the solar chimney. The power generation mechanism in this system is to turn the wind turbine placed inside a high rise cylindrical hollow tower by an induced thermal updraft. As long as the thermal updraft is induced inside the tower by the solar radiation, this system can produce electricity. The disadvantage of this system is the low power generation efficiency compared to other solar energy power generation systems. To overcome this disadvantage, we improved the mechanism in order to augment the velocity of the air which flows into the wind turbine. By applying a diffuser tower instead of a cylindrical one, the efficiency of the systems power generation is increased. The mechanism that we investigated was the effect of the diffuser on the solar chimney structure. The inner diameter of the tower expands as the height increases so that the static pressure recovery effect of the diffuser causes a low static pressure region to form at the bottom of the tower. This effect induces greater airflow within the tower. The laboratory experiment, as does the computational fluid dynamics (CFD) analysis of the laboratory sized model, shows that the proposed diffuser type tower induces a velocity approximately 1.38–1.44 times greater than the conventional cylindrical type. The wind power generation output is proportional to the cube of the incoming wind velocity into the wind turbine; therefore, approximately 2.6–3.0 times greater power output can be expected from using the diffuser type tower.

Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage

Present wind power is intermittent and cannot be used as the baseload energy source. Concept study of wind power utilizing direct thermal energy conversion and thermal energy storage named Wind powered Thermal Energy System (WTES) is conducted. The thermal energy is generated from the rotating energy directly at the top of the tower by the heat generator, which is a kind of simple and light electric brake. The rest of the system is the same as the tower type concentrated solar power (CSP). The cost estimation suggests that the energy cost of WTES is less than that of the conventional wind power, which must be supported by the backup thermal plants and grid enhancement. The light heat generator reduces some issues of wind power such as noise and vibration.

Design Features and Control Concepts of ALSTOM Molten Salt Receiver

The tower type molten salt solar thermal power plant consists of a large heliostat field consisting of thousands of mirrors with capabilities to track the sun, positions itself in order to reflect the solar energy onto the molten salt central receiver (MSCR) atop a tower optimally located in the heliostat field. The receiver consists of tube banks arranged in panels with molten nitrate salt flowing within. The concentrated energy from the heliostat field heats the molten salt from 290oC to 565oC while it passes through the receiver. The hot molten salt is stored in a tank and utilized to produce steam for power generation as per the demand. The molten salt central receiver serves as the interface between the solar field and the molten salt heat transfer medium. The various components comprising the MSCR have been designed to maximize the received solar energy, the transfer of solar energy to salt, and the capacity of hot salt production. The state of the art for molten salt central receiver technology offer new opportunities to optimize the design and control of the same. This paper discusses the advanced design features and control concepts of the ALSTOM molten salt central receiver. It includes an optimized receiver surface to minimize pressure drop while maximizing the utilization of the heliostat field, modular design which is easy to construct and maintain, multiple system features for controlling salt temperatures and a health monitoring system for accurate, on-line life assessment, as prominent features.

Casson towers and filtrations of the smooth knot concordance group

The n-solvable filtration $\{\mathcal{F}_n\}_{n=0}^\infty$ of the smooth knot concordance group (denoted by $\mathcal{C}$), due to Cochran-Orr-Teichner, has been instrumental in the study of knot concordance in recent years. Part of its significance is due to the fact that certain geometric characterizations of a knot imply membership in various levels of the filtration. We show the counterpart of this fact for two new filtrations of $\mathcal{C}$ due to Cochran-Harvey-Horn, the positive and negative filtrations, denoted by $\{\mathcal{P}_n\}_{n=0}^\infty$ and $\{\mathcal{N}_n\}_{n=0}^\infty$ respectively. In particular, we show that if a knot K bounds a Casson tower of height n+2 in the 4-ball with only positive (resp. negative) kinks in the base-level kinky disk, then K is in $\mathcal{P}_n$ (resp. $\mathcal{N}_n$). En route to this result we show that if a knot K bounds a Casson tower of height n+2 in the 4-ball, it bounds an embedded (symmetric) grope of height n+2, and is therefore, n-solvable (this also implies that topologically slice knots bound arbitrarily tall gropes in the 4-ball). We also define a variant of Casson towers and show that if K bounds a tower of type (2,n) in the 4-ball, it is n-solvable. If K bounds such a tower with only positive (resp. negative) kinks in the base-level kinky disk then K is in $\mathcal{P}_n$ (resp. $\mathcal{N}_n$). Our results show that either every knot which bounds a Casson tower of height three is topologically slice or there exists a knot which is not topologically slice but lies in each $\mathcal{F}_n$. We also give a 3-dimensional characterization, up to concordance, of knots which bound kinky disks in the 4-ball with only positive (resp. negative) kinks; such knots form a subset of $\mathcal{P}_0$ (resp. $\mathcal{N}_0$).

Electrical field computation of polymeric insulator using reduced dimension modeling

In recent years, electrical field distribution is the area of major concern in the service life of Polymeric Insulators. Several methodologies are proposed to analyze the electrical field along the insulators both experimentally and numerically of which the former might be very time consuming requiring a number of trial-error tests to determine the optimum dimensions. The advent of super computers makes numerical analyses feasible on any complex geometry modeled in 3-D and the overall optimization techniques to control the electrical field become quite easier. However, the main drawbacks in 3-D analyses are the more computation time and memory, making it desirable to simplify the structure. Hence a methodology based on relationship between electrical field profiles of 2-D (axi-symmetry model of insulator with corona ring) and 3-D model (insulator with corona ring, tower, 3 phase hardware fittings and conductors) for a dimension and location of corona/grading rings is proposed. Based on the relationship, electrical field profiles of 3-D models are predicted for different dimension and location of rings using its equivalent 2-D model electrical field profile. Commercially available 2-D and 3-D finite element based electrostatic field computation program is used. A 220 kV suspension type I string assembly is used for this study. Later, the approach is validated for 132 kV and 400 kV insulators. The type of tower, string configuration is kept constant throughout the analyses.

A Method Study on Apartment Building Layout for Enhancing Resident’s View - Mainly with Evolutionary Exploration on Open Air View at Tower Type Apartment -

A Method Study on Apartment Building Layout for Enhancing Resident’s View - Mainly with Evolutionary Exploration on Open Air View at Tower Type Apartment -

On individual design and selection of towers for overhead power lines

Main trends in the development of the individual design of the overhead power lines are discussed. Methods for calculating the integrated strength characteristics of the overhead lines with sequential application of the CAD SolidWorks and ANSYS Workbench programs are set forth. The reliabilities of three line segments supported by towers of different types depending on the climatic conditions are compared. A modular simulation model allows calculating integral mechanical loads on overhead power line towers for various atmospheric conditions in terms of ambient temperature, ice loading, and wind force. The mechanical analysis of the overhead power lines is based on consideration of the material and the design of the towers, the type of insulators, and the cross sections of the conductors and the ground wires. Simple and versatile methods for well-grounded selection of the tower type and structural members for designing overhead power lines are proposed. The results of calculations enable the most reliable climatic conditions of operating the overhead power lines to be identified.

The Helixes of Vittorio Bonadè Bottino: Symbolism, Geometry and Architectural Types

The works of Vittorio Bonade Bottino, engineer, were deeply linked to the affirmation and development of the Italian FIAT car industry, for which he worked from 1919, when he began to collaborate in the realization of the Lingotto factory in Turin. His relationship with FIAT grew over time and led him to assume increasingly important assignments. Among these were the social architectures that he designed for the company during the 1930s. The most representative were the two hotel towers in Sestriere and the colonies of Marina di Massa in Tuscany and Sauze d’Oulx in Piedmont; here he tested and consolidated his innovative architectural type of the cylindrical tower, where the helix represents the geometric matrix and the compositional key of the whole structure.

Vertical structure of cumulonimbus towers and intense convective clouds over the South Asian region during the summer monsoon season

AbstractThe vertical structure of radar reflectivity factor in active convective clouds that form during the South Asian monsoon season is reported using the 2A25 version 6 data product derived from the precipitation radar measurements on board the Tropical Rainfall Measuring Mission satellite. We define two types of convective cells, namely, cumulonimbus towers (CbTs) and intense convective cells (ICCs). CbT is defined referring to a reflectivity threshold of 20 dBZ at 12 km altitude and is at least 9 km thick. ICCs are constructed referring to reflectivity thresholds at 8 km and 3 km altitudes. Cloud properties reported here are based on 10 year climatology. It is observed that the frequency of occurrence of CbTs is highest over the foothills of Himalayas, plains of northern India and Bangladesh, and minimum over the Arabian Sea and equatorial Indian Ocean west of 90°E. The regional differences depend on the reference height selected, namely, small in the case of CbTs and prominent in 6–13 km height range for ICCs. Land cells are more intense than the oceanic ones for convective cells defined using the reflectivity threshold at 3 km, whereas land versus ocean contrasts are not observed in the case of CbTs. Compared to cumulonimbus clouds elsewhere in the tropics, the South Asian counterparts have higher reflectivity values above 11 km altitude.

Calculating the Surface Potential Gradient of Overhead Line Conductors

The surface potential gradient is a critical design parameter for planning overhead lines since it determines the level of corona loss, radio interference, and audible noise. The majority of existing surface gradient calculations are based on analytical methods which restrict their application in simulating complex surface geometry. This paper proposes a novel method which utilizes both analytical and numerical procedures to predict the surface gradient. With this method, stranding shape, protrusions, the proximity of tower, the type of tower, bundle spacing, and bundle arrangement can be taken into consideration when calculating surface potential gradients. A sensitivity study on the factors affecting surface gradient distribution is performed.

High-efficiency parallel-plate wet scrubber (PPWS) for soluble gas removal

A parallel-plate wet scrubber (PPWS) was designed and tested to control low-concentration soluble acid gases using a multi-parallel-plate module (MPPM) to replace typical tower packings. The parallel plates in the MPPM were made of polypropylene coated with nano-TiO2 particles to enhance hydrophilicity for scrubbing liquid to form uniform liquid film. The gap between the plates was maintained at 3mm, providing channels through which soluble gas pollutants in the upward gas stream were absorbed by the downward scrubbing liquid film on the surfaces. The removal efficiency was tested using HCl, HNO3, and CH3COOH of 0.02–2ppmv at different retention times and liquid-to-gas ratios. Results show that when the retention time was 0.1, 0.3 and 0.5s, the removal efficiency of the present scrubber for HCl, HNO3, and CH3COOH in low concentration was greater than 91%, 95%, and 98%, respectively. The MPPM significantly enhances the removal efficiency of the present scrubber, especially in low inlet concentration range (0.02–1ppmv), which was greater than 99% for HCl and HNO3 and 98% for CH3COOH at the liquid-to-gas ratio of 18.5L/m3, the retention time of 0.5s, and the pressure drop of 0.2cm H2O. The experimental removal efficiencies of the MPPM are in good agreement with theoretical predictions. It is expected that the present PPWS can be scaled up as an efficient control device with low pressure drop for low-concentration soluble acid and basic gases.

Experimental Assessment of Water Sprays Utilization for Controlling Hydrogen Sulfide Releases in Confined Space

This paper reported the utilization of water spray for controlling H2S release in a confined space, which is especially important in industry. A typical spray tower was modified to simulate the confined space for people's enterable routine operation (e.g., pump room), in which the dilution capacity of water sprays can also be evaluated. This work consists of two parts: the first part focuses on the influences of different operating conditions on chemical dilution capacities of water sprays in mechanisms; the second one is comparison between two nozzle configurations for evaluating their feasibilities of practical application. Water sprays express eligible performance for H2S release control even though their dilution capacity was weakened at high gaseous concentrations and rates of releases. The presence of Na2CO3can significantly improve absorption effectiveness of H2S in water and the optimal Na2CO3additive was found to be 1.0 g·L−1in this test. Compared with Na2CO3, adjusting water flow rate may be an effective strategy in enhancing dilution capacity of water sprays due to the fact that larger flow rate led to both less dilution time (TD) and dilution concentration (CD). Furthermore, multinozzle configuration is more efficient than single-nozzle configuration under the same water consumption.

Воссоздание рабочих методов для построения архитектурных форм двух храмов первой половины XVI века

The article is dedicated to the review of the erecting process for tower type cult structures in early 16thcentury Russia. Since there are common laws for military, civil and religious architecture, the author is trying to solve the problem by using the erecting method for tower type of civil constructions described by Alberti in the analysis of religious buildings of the same type. The article also contains a detailed study of volumetric composition of the Church of St. John Climacus and the Church of the Ascension in Kolomenskoye village. The author comes to the conclusion that Italian architects of these churches used the method described by Alberti, and that, as evidence shows, they could use some decorative elements from the image of the original facade of the church of Santa Maria del Fiore in their work.

ICOPE-15-C148 Study on Convective Heat Transfer and Wall Temperature in the Furnace of 1000MW Tower Type Boiler

ICOPE-15-C148 Study on Convective Heat Transfer and Wall Temperature in the Furnace of 1000MW Tower Type Boiler

Singly periodic free boundary minimal surfaces in a solid cylinder of $\mathbb{R}^3$

The aim of this work is to show the existence of free boundary minimal surfaces of Saddle Tower type which are embedded in a vertical solid cylinder in $\mathbb{R}^3$ and invariant with respect to a vertical translation. The number of boundary curves equals $2l$, $l \ge 2$.These surfaces come in families depending on one parameter and they converge to $2l$ vertical stripes having a common vertical intersection line.Such surfaces are obtained by perturbing the symmetricallymodified Saddle Tower minimal surfaces.

국내 종합병원의 형태 유형 변화에 관한 연구

This study selects factors affecting form type of hospital architecture by considering studies and references on hospital architecture type in korea and other countries in general. Also this study classifies general hospitals chronologically and analyzes type change of general hospitals in relation with periodic change of healthcare environment. Through this, this study aims to analyze chronological change of general hospitals' form type and provide the current of hospital architecture's general type. The form type classification of this study is classification according to the form of ward, classification according to the relationship between ward and D.T.D(Diagnostic and Treatment department), classification according to the relationship between O.P.D(Out Patient department) and D.T.D, classification according to the rate of centralization, classification according to the circulation system. The form type of ward changed from plate type to tower type, and the circulation system of ward changed from middle corridor to double corridor, the number of Team Nursing chaged from 1 to 2 in 1990. On the other hand the chage of others classifications took place from 1990' to 2010'. It is judged that this overall change is appeared by a change from an inpatien-oriented system to an outpatient-oriented system followed by an increase in number of outpatients, an increase in amenities in ground floor and adoption of healing environment for patients and visitors.

Selection of an optimal lattice wind turbine tower for a seismic region based on the Cost of Energy

Over the past few decades, wind has emerged as one of the major sources of green and renewable energy for being a cost effective solution and offering a substantial reduction in greenhouse gas emissions. Currently, onshore wind energy is undergoing a rapid development and expansion at an annual rate of approximately 27%. As such, more and more wind farms are being established in earthquake prone areas resulting from the availability of wind energy in these regions. This paper investigates the optimal selection of lattice wind turbine towers in seismic regions based on the Cost of Energy (COE). Although, various different tower types and materials (e.g., steel and concrete-steel composite monopole) are available, this study focuses on steel lattice towers for providing a cost effective solution and for posing a challenging structural optimization problem. To the knowledge of the authors, design optimization of lattice wind turbine towers subjected to combined earthquake, wind and gravity loading has not been performed before. Ten tower height-wind turbine size combinations are generated by placing turbines with 100 to 400 kW power generation capacity on towers having 24 to 42.6 m height, and a cost optimal solution is obtained for each combination. Taboo search algorithm is used to minimize the total cost. The wind and earthquake loads on the towers are obtained for a specific case study location. The COE for each combination is calculated using three different wind probability distributions. Instead of using simplified structural models, all the details of a rigorous structural analysis, e.g., geometric nonlinearity, are included in the finite element models. Realistic loading conditions, including wind and earthquake, are considered.