A study into the influence of the car geometry on the aerodynamic transient effects arising in a high rise lift installation

One of the main goals in designing a high-speed lift system is developing a more aerodynamically efficient car geometry that guarantees a good ride comfort and reduces the energy consumption. In this study, a three-dimensional computational fluid dynamics (CFD) model has been developed to analyse an unsteady turbulent air flow around two cars moving in a lift shaft. The paper is focused on transient aerodynamic effects arising when two cars pass each other in the same shaft at the same speed. The scenarios considered in the paper involve cars having three different geometries. Aerodynamic forces such as the drag force that occur due to the vertical opposite motions of the cars have been investigated. Attention is paid to the airflow velocity and pressure distribution around the car structures. The flow pattern in the boundary layer around each car has been calculated explicitly to examine the flow separation in the wake region. The results presented in the paper would be useful to guide the lift designers to understand and mitigate the aerodynamic effects arising in the lift shaft

Computational analysis of the fluid-structure interaction occurring in a model of two vehicles overtaking each other

A computational study has been conducted to investigate the transient aerodynamic forces experienced by two vehicles overtaking each other. Ahmed body model has been used to represent the vehicles. The transient effects during the overtaking scenario have been determined by using a Computational Fluid Dynamics (CFD) model. This has been achieved by developing an open source computational code. The aerodynamic effects have been investigated by emulating this event in a virtual wind tunnel. One of the generic vehicles was set to be stationary, while the other was allowed to be moving at constant speed. The Delayed Detached Eddy simulation (DDES) turbulence approach has been applied in this study based on the finite volume analysis (FVA). The computational results such as fluid forces and moments acting on the vehicle structures have been compared against published experimental results. Encouraging correlations between those results are observed. In the present work, the fluid-structure interaction (FSI) phenomenon has also been studied by developing a flexible body dynamic model. The modal and dynamic responses are determined from FEM analysis by the application of fluid transient loads obtained from the CFD model. This investigation is important to address the issue of stability and performance of the vehicle system. This work provides a significant understanding into the complex aerodynamics of an overtaking process and gives the foundation for further analysis in the area of fluid-structure interactions for more complex geometries and scenarios

Computational analysis of the fluid-structure interaction occurring in a model of two vehicles overtaking each other

A computational study has been conducted to investigate the transient aerodynamic forces experienced by two vehicles overtaking each other. Ahmed body model has been used to represent the vehicles. The transient effects during the overtaking scenario have been determined by using a Computational Fluid Dynamics (CFD) model. This has been achieved by developing an open source computational code. The aerodynamic effects have been investigated by emulating this event in a virtual wind tunnel. One of the generic vehicles was set to be stationary, while the other was allowed to be moving at constant speed. The Delayed Detached Eddy simulation (DDES) turbulence approach has been applied in this study based on the finite volume analysis (FVA). The computational results such as fluid forces and moments acting on the vehicle structures have been compared against published experimental results. Encouraging correlations between those results are observed. In the present work, the fluid-structure interaction (FSI) phenomenon has also been studied by developing a flexible body dynamic model. The modal and dynamic responses are determined from FEM analysis by the application of fluid transient loads obtained from the CFD model. This investigation is important to address the issue of stability and performance of the vehicle system. This work provides a significant understanding into the complex aerodynamics of an overtaking process and gives the foundation for further analysis in the area of fluid-structure interactions for more complex geometries and scenarios

Modelling and computer simulation of aerodynamic interactions in high-rise lift systems

The aerodynamic effects that occur when a high-speed lift travels through the hoistway involve a range of diverse phenomena that lead to excessive vibrations of the sling-car assembly and noise inside the hoistway and the car. Noise and vibration may then be transmitted to the building structure. Thus, a good understanding and prediction of aerodynamic phenomena occurring in high-speed lift installations is essential to design a system which satisfies ever more demanding ride quality criteria. This paper discusses the fluid-structure interactions taking place in high-rise applications and presents the results of a study to develop a computational model to predict the aerodynamic interactions in high-speed lift systems using Multibody Dynamics (MBD) and Computational Fluid Dynamics (CFD) techniques. The model is implemented in a high- performance computer simulation and 3D visualisation platform. It is demonstrated that the model can be deployed as a tool for aerodynamic design and optimization of high-rise lift systems