Tunnels and foundation pits are two separate types of excavation that frequently used in urban settings. Excavating tunnels sequentially around existing pile foundations is becoming more prevalent as underground space utilization rates increase. The deformation load transfer mechanisms the group under asymmetric conditions “first tunnel, then pit” pit, tunnel” studied from perspective relative ...

Taking the soft rock portal section of Baiyunding Tunnel as research background, it is proposed that combination rigid and flexible anti-vibration measures can more effectively improve seismic performance tunnel. Through shaking table model test, effects structural reinforcement, installation shock absorbing joint, are compared analyzed. The test data shows that: only strengthening taken, minim...

In the present paper, a supersonic wind-tunnel is designed to maintain a flow with Mach number of 3 in a 30cm×30cm test section. An in-house CFD code is developed using the Roe scheme to simulate flow-field and detect location of normal shock in the supersonic wind-tunnel. In the Roe scheme, flow conditions at inner and outer sides of cell faces are determined using an upwind biased algorithm. ...

Models are presented for the aerodynamic coefficients of Supersonic Ringsail and Disk-Gap-Band parachutes as functions of total porosity, λT, Mach number, M, and total angle of attack, αT (when necessary). The source aerodynamic coefficients data used for creating these models were obtained from a wind tunnel test of subscale parachutes. In this wind tunnel test, subscale parachutes of both par...

Abstract: An inflatable cell model of paragrlider’s wing canopy has been investigated in wind tunnel experiments, which is designed to represent the dynamic behaviors of each cell comprising the canopy. Effects of air-intake of paraglider canopy have also been investigated in this study. The improvement of the shape of air intake and pressure distribution from the standpoints of aerodynamics wi...

A lightweight flapping-wing micro air vehicle (MAV) was designed and built and successfully filed in the sky. The unsteady aerodynamics associated with this MAV was detailedly studied by using the method of computational fluid dynamics (CFD).The variations of different parameters of the flapping MAV, such as flapping amplitude, pitch amplitude and flapping frequency, were investigated with nume...

New rotor blades are to be fabricated for the 24 foot diameter, 3-stage axial compressor which provides airflow in the 11by 11-Foot Transonic Wind Tunnel Facility at NASA Ames Research Center in Moffett Field, California. This presents an opportunity to increase the peak Mach number capability of the tunnel by redesigning the compressor for increased pressure ratio. Simulations of the existing ...

A method for accurately measuring the drag associated with a protuberance on an aircraft has been devised and implemented in a wind tunnel using a C-130 model. The C-130 aircraft has been heavily modified for various different configurations and the impact that these modifications have had on the aerodynamic performance of the aircraft has not been well documented. This paper describes a method...

nowadays deep excavations are needed for construction of foundation of high rise buildings, providing space for parking and etc. in some cases deep excavations may be constructed in the vicinity of the subway tunnels and causes unpredicted extra displacements and internal forces in tunnel lining of tunnels which were not designed for them and consequently affect serviceability of tunnel. theref...