13 research outputs found
Numerical Investigations of the Effects of Sidewall Compression and Relaminarization in 3D Scramjet Inlet
No full textThis 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. The computed wall pressure and heat transfer in the symmetry plane are in close agreement with the measurements and numerical results indicate that sidewall compression alters the inlet performance significantly. The effects of relaminarization over the expansion corner prior to the interior part of the inlet is isolated and studied in both experiment and simulation
Effects of Sidewall Compression and Relaminarization in a Scramjet Inlet
No full textThis 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 computed wall pressure and heat transfer in the symmetry plane are in close agreement with the measurements, and the numerical results indicate that the weak sidewall compression alters the inlet performance significantly. The effects of partial relaminarization over the expansion corner, before the interior part of the inlet, is isolated and investigated in both the experiment and simulation. It is shown that relaminarization of a boundary layer is predicted accurately using the current numerical methods. This work represents a contribution to the understanding of the effects of sidewall compression and relaminarization in designing a scramjet inlet
Numerical Investigation of Wall Temperature and Entropy Layer Effects on Double Wedge Shock / Boundary Layer Interactions
No full textA combined experimental as well as computational analysis of hypersonic flows over heated ramp and wedge configurations has been initiated. This paper presents an overview of the ongoing work on the numerical simulation using two different, well validated Reynolds averaged Navier–Stokes solvers with a variety of turbulence models. Different surface temperatures are specified to investigate the impact on the shock / boundary layer interaction and on the size of the separation. To analyze the effect of an entropy layer behind a blunt leading edge on the structure of the boundary layer as well as on the development of the inviscid flow field, flows over double wedge configurations with different nose radii are computed and compared to the experimental result
COMPUTATION OF WALL HEAT FLUXES IN HYPERSONIC INLET FLOWS
No full textWithin the frame of the German Collaborative Research Center SFB 253 “Funda-mentals of Design of Aerospace Planes”, generic supersonic and hypersonic engine inlet configurations are investigated both numerically and experimentally. This paper presents an overview of the ongoing work on the numerical simulation of high-speed inlet flows solving the complete Reynolds averaged Navier-Stokes equation with a block-structured, cell-centered finite-volume method. The turbulence model is Wilcox’s low Reynolds num-ber k − ω model with some extensions for modeling high-speed wall-bounded flows and separation regions. The first configuration involves a supersonic inlet with interior com-pression and the development of a subsequent shock train. This test case is mainly used to demonstrate the present state of a newly implemented advanced multigrid method for supersonic turbulent flows. Of recent interest is the accurate prediction of wall heat transfer rates in the second test configuration. This configuration is a heated compression ramp model which is presently investigated experimentally in a shock tube to assess the influence of the wall temperature on boundary layer separation behavior
Measuring the effect of customer relationship management (CRM) components on the non financial performance of commercial banks: Egypt case
No full textThis paper presents customer relationship management (CRM) components as applied on the Egyptian Commercial Banks, examined from the bankers' point of view. Then, it intends to measure their effect on the level of customer satisfaction and loyalty from the customers’ point of view as examples of the non financial performance measures. The paper is quantitative in nature and consists of two different structured questionnaires using convenience/quota sampling. The first involved 180 employees in order to measure CRM applicability, and the second involved 270 customers to measure the level of customer satisfaction and loyalty and their effect on the Egyptian Commercial Banks' financial performance The findings show that the selected banks apply CRM components but the level of application differs from one bank to another. The results showed a significant positive relationship between CRM and customer satisfaction in the Egyptian Commercial Banks, when applying them together and not separately. In addition, there is a strong positive effect between customer satisfaction and loyalty which was reflected on the Commercial Banks' financial performance. The findings confirm the importance of studying and implementing CRM to achieve customer loyalty and improve the Egyptian Commercial Banks financial performance. Banks wishing to improve their relationships with customers need to focus on the CRM components to develop relevant and effective marketing strategies and tactics. The paper measures the CRM as a multidimensional construct as applied on the Egyptian Commercial Banks and relate it to the achievement of the ultimate goal of retaining customers to gaining a sustainable competitive advantage and achieve more profits
