Numerical Analysis of Elevator Piston Effect on Building Airflow for an Air-Conditioned High-Rise Building in Winter

2014 ◽  
Vol 1008-1009 ◽  
pp. 1068-1074 ◽  
Author(s):  
Yan Wang ◽  
Yan Ling Guan ◽  
Yuan Sheng Yin

A model of a 24-storey building (94.5m high) with air-conditioning system was developed to analyze the elevator piston effect on building airflow by dynamic mesh technique of computational fluid dynamics (CFD). The results of the pressure distribution and airflow paths show that with the upward movement of elevator cabs, due to the elevator piston effect, changes in the pressure distribution and airflow paths occur in all the building; the pressure difference across the elevator door is enlarged, which is likely to cause some security issues; but the air exfiltration rate is hardly affected.

Author(s):  
Hui Yang ◽  
Li Jia ◽  
Lixin Yang

The three dimensional air temperature distributions on subway platform under both natural ventilation mode and over-platform supply/ under-platform exhaust (OSUE) air conditioning system were simulated during a single train entering, staying and departing processes by using Computational Fluid Dynamics (CFD) method. On basis of the simulation, the comprehensive influences of both the train’s piston effect and the air conditioning mode on the air environment in different part of the platform were analyzed.


2013 ◽  
Vol 291-294 ◽  
pp. 1880-1883
Author(s):  
Li Ping Xiang

A numerical model to improve the air-conditioning system of vehicle cabin taking into the cabin air moisture and its transport by the airflow within the enclosure cabin is described. An efficient computational fluid dynamics(CFD) technique is using the “realisable” model. The temperature and humidity fields in the passenger cabin are investigated individually under having or no body moisture. The temperature in the vehicle cabin taking into account human moisture is lower than no taking into account moisture 0.5 °C. The human dispersing moisture effect significantly on the humidity, which lead to the humidity is elevating and the humidity in vehicle cabin is corresponded hygienic standard.


Author(s):  
Chinmay Padole ◽  
Samiksha Bansod ◽  
Taniya Sukhdeve ◽  
Abhishek Dhomne ◽  
Maheshwari Nagose ◽  
...  

ETABS stands for Extended Three-Dimensional Analysis of Building Systems. ETABS is commonly used to analyze: Skyscrapers, concrete structures, low and high rise buildings, and portal frame structures. The case study in this paper mainly emphasizes on structural behavior of multi-storey building for different plan configurations like rectangular, C, L and I-shape. Modelling of 15-storeys R.C.C. framed building is done on the ETABS software for analysis ETABS issue, for analysis and design for building systems. ETABS features are contain powerful graphical interface coupled with unmatched modeling, analytical, and design procedures, all integrated using a common database. STAAD and ETABS both of the software are well equipped and very much capable of handling different shape of the structures, static and dynamic loadings and different material properties.


2020 ◽  
Vol 10 (23) ◽  
pp. 8573
Author(s):  
Franco Concli

For decades, journal bearings have been designed based on the half-Sommerfeld equations. The semi-analytical solution of the conservation equations for mass and momentum leads to the pressure distribution along the journal. However, this approach admits negative values for the pressure, phenomenon without experimental evidence. To overcome this, negative values of the pressure are artificially substituted with the vaporization pressure. This hypothesis leads to reasonable results, even if for a deeper understanding of the physics behind the lubrication and the supporting effects, cavitation should be considered and included in the mathematical model. In a previous paper, the author has already shown the capability of computational fluid dynamics to accurately reproduce the experimental evidences including the Kunz cavitation model in the calculations. The computational fluid dynamics (CFD) results were compared in terms of pressure distribution with experimental data coming from different configurations. The CFD model was coupled with an analytical approach in order to calculate the equilibrium position and the trajectory of the journal. Specifically, the approach was used to study a bearing that was designed to operate within tight tolerances and speeds up to almost 30,000 rpm for operation in a gearbox.


Author(s):  
Alaa Hasan ◽  
Tarek ElGammal ◽  
Ryoichi S. Amano ◽  
Essam E. Khalil

Accurate control of thermal conditions in large space buildings like an underground metro station is a significant issue because passengers’ thermal comfort must be maintained at a satisfactory level. The large eddy simulation (LES) model was adopted while using the computational fluid dynamics (CFD) software “STAR CCM+” to set up a CFD station model to predict static air temperature, velocity, relative humidity and predicted mean vote (PMV), which indicates the passengers’ thermal comfort. The increase in the number of passengers using the model station is taken into consideration. The studied cases covered all the possible modes of the station box, these modes are (1) the station box is empty of trains, (2) the presence of one train inside the station box, (3) the presence of two trains inside the station box. The objective is to bring the passengers’ thermal comfort in all modes to the acceptable level. The operation of under platform exhaust (UPE) system is considered in case of train presence inside the station box. The use of UPE is more energy efficient than depending entirely on the air conditioning system to maintain the thermal conditions comfortable.


2015 ◽  
Vol 769 ◽  
pp. 29-35
Author(s):  
Olga Ivankova ◽  
Lenka Konecna

Static and dynamic analysis of the high-rise (24-storey) building is discussed in this paper. The influence of the change of load-bearing system on its stiffness in the case of seismic event was detected. Two different load-bearing systems were chosen – the wall system (alt.1) and the skeleton system (alt.2). Finite element method was used for the solution of 3D computing models. Short description of the building, used material, applied load, a type of the subsoil and obtained results are mentioned. Dynamic analysis was repeated for four various seismic areas in Slovakia.


2019 ◽  
Vol 969 ◽  
pp. 247-252
Author(s):  
S. Neelavathi ◽  
K.G. Shwetha ◽  
C.L. Mahesh Kumar

In the present situation the growth of population is increasing rapidly. In view of this, the development of the buildings are changing its dimension to high rise structures further having trends of structural irregularities. These kinds of irregularities in the structure cannot be avoided as it is more vulnerable to the seismic actions. The structure fails by the uneven moments created by the seismic actions because of the irregularities in the structure which is based on the parameters like storey drift, displacement, torsional effects etc., In this paper the effects of the torsional irregularity is studied and the failure has been minimized by adding necessary elements like shear wall and bracings where ever required. In Present study we have considered the 20 storey building of reinforced concrete structure which includes five models of different regular and irregular shaped structures which are subjected to earthquake load and are modeled by using ETABS version 9. Analysis results elaborate the parameters like displacement, time period, storey drift and comparisons of the results among the set of models.


2013 ◽  
Vol 19 (6) ◽  
pp. 811-822 ◽  
Author(s):  
Mohammed Jameel ◽  
A. B. M. Saiful Islam ◽  
Mohammed Khaleel ◽  
Aslam Amirahmad

A multi-storey building is habitually modelled as a frame structure which neglects the shear wall/slab openings along with the inclusion of staircases. Furthermore, the structural strength provided by shear walls and slabs is not precisely incorporated. With increasing building height, the effect of lateral loads on a high-rise structure increases substantially. Inclusion of shear walls and slabs with the frame leads to improved lateral stiffness. Besides, their openings may play imperative role in the structural behaviour of such buildings. In this study, 61 multi-storey building configurations have been modelled. Corresponding analyses are performed to cope with the influence of shear walls, slabs, wall openings, masonry walls and staircases in addition to frame modelling. The finite element approach is used in modelling and analysis. Structural responses in each elemental combination are evaluated through equivalent static and free vibration analyses. The assessment reveals that inclusion of only slab components with frame modelling contributes trivial improvement on structural performance. Conversely, the presence of shear wall slabs with frame improves the performance noticeably. Increasing wall openings decreases the structural responses. Furthermore, it is not recommended to model staircases in addition to frame–slab–shear wall modelling, unless the effect of wall openings and slab openings is adequately considered.


Sign in / Sign up

Export Citation Format

Share Document