Tue Nguyen

• Engineer at General Electric

In the present paper, an approach for scaling the aerodynamics of advanced seals is presented. Modern advanced seals, such as a self-adaptive gas lubricated face seal, comprise elements that are commonly used in turbomachinery sealing. These are labyrinth seals and mechanical face seals. Parameters influencing the aerodynamical and mechanical behav...

This paper is dedicated to experimental and numerical investigations of self-adaptive seals under 2D static conditions. Besides the leakage flow across the seal / rotor combination, the distribution of static pressures within the air bearing clearance is measured. The bearing face flow is studied extensively, focusing on its dependency to the diffe...

In the present paper an approach for scaling the aerodynamics of advanced seals is presented. Modern advanced seals, such as a self-adaptive gas lubricated face seal comprise elements that are commonly used in turbomachinery sealing. These are labyrinth seals and mechanical face seals. Parameters influencing the aerodynamical and mechanical behavio...

Today's industrial gas turbines are required to cope with strong fluctuations caused by a strongly varying feed of renewable energies into the grid. These transient operating conditions result in high temperature gradients and consequently lead to increased axial and radial displacements of turbine parts. Such flexible operations need to be support...

We examine the effects of compressibility, slip, and fluid inertia on the frequency response of particle-based velocimetry techniques for supersonic and hypersonic flows by solving the quasi-steady drag equation for solid, spherical particles. We demonstrate that non-continuum and fluid inertial effects significantly affect the particle response un...

The design of a miniature ramjet combustor using gaseous methane fuel for Mach 2.5 has been conducted. The main challenges stem mainly from the insufficient space for mixing and burning, short residence time, and the flame stabilization. Impossible utilization of relatively large air-blast fuel injectors provides more difficulties for the design. T...

In this paper, the effects of boattail junction shaping on aerodynamic drag and stability of supersonic spin-stabilized rounds are investigated using computational fluid dynamics. For a generic round body comprising of a secant-ogive nose, a cylindrical body and a conical boattail, the shaping technique was achieved by adding a convex surface of va...

This paper presents a wind tunnel investigation of the aerodynamic performance of two high performance supersonic rounds: the standard 155 mm M549 projectile and a new optimum round that was redesigned from the standard round. The experiments were performed over a wide range of Mach numbers ( , 2, 2.5, 3, 3.5, and 4) providing new data for the cons...

The main challenges in designing a small-size combustor operating at relatively high throughflow speeds are the limited available space for mixing and burning due to the short residence time of mixtures and the difficulties in flame stabilization. The trapped vortex combustor (TVC) is investigated as an approach to provide fuel-air mixing and flame...

The main challenges in designing a small-size combustor operating at relatively high throughflow speeds are the insufficient space for mixing and burning due to the short residence time of mixtures and the difficulties in flame stabilization. In this study, the trapped vortex combustor (TVC) concept is investigated because it provides a more stable...

An optimisation procedure coupled with computational fluid dynamics (CFD) is proposed to minimise the aerodynamic drag and to improve the static and dynamic stabilities of generic rounds at supersonic speeds (Mach 1·5 to 4). First, the Active-set algorithm, Sequential Quadratic Programming (SQP) is used as the optimisation method for drag minimisat...

This paper presents the numerical simulations and the performance analysis of a scramjet inlet as part of a combined experimental and numerical study. A well-validated finite volume flow solver was used to simulate a scramjet inlet with a double ramp configuration for outer compression, including varying degrees of sidewall compression. The compute...

This paper presents grid adaptive Reynolds-averaged Navier-Stokes (RANS) simulations of turbulent jet injection in subsonic crossflow. Three different velocity ratios, which are commonly encountered in film cooling and combustion applications, are considered. The simulations are performed using a well-validated flow solver and an eddy viscosity mod...

This paper presents the Reynolds-averaged Navier-Stokes simulations of successive perturbations in supersonic turbulent flows that are normally encountered in a scramjet intake. Two forward-facing ramps are considered in which the flow is turned through 20 deg compression and 20 deg expansion successively. The first ramp is with sharp corners, and...

In this paper, the development of a new ω-based Reynolds stress model that is consistent with asymptotic analysis in the near wall region and with rapid distortion theory in homogeneous turbulence is reported. The model is based on the SSG/LRR-ω model developed by Eisfeld (2006) with three main modifications. Firstly, the near wall behaviors of the...

This paper presents the numerical simulations and performance analysis of a 3D scramjet inlet with focus on the effects of sidewall compression and relaminarization. A well-validated �finite volume flow solver was used to simulate a scramjet inlet with a double ramp configuration for outer compression and varying degrees of sidewall compression. Th...

This paper presents a combined study of simulation and experiment of hypersonic intake flow. A finite-volume flow solver is used to simulate a scramjet intake configuration and the results are compared against the measurements. Turbulence closure is achieved using two eddy-viscosity models and a differential Reynolds-stress model. In order to impro...

This paper presents an ongoing project on numerical investigation of the rapid distortion and the subsequent relaxation of compressible turbulent boundary layers over expansion corners. A well-validated finite volume flow solver comprising several turbulence models was used to simulate two test cases of supersonic flows encountering abrupt expansio...

The design, analysis and optimization of a new stator concept for multistage centrifugal compressors using numerical methods is presented. The first objective was to further improve the performance of a well-optimized stage with a short vaneless diffuser, see Aalburg et al [1]. The second objective was to achieve a significant increase in the flow...