Aerodynamic Functional Diagnostics Based on Angular Momentum Transport Lines

In analogy with the classical concept of mass-flux-based streamlines, we define angular momentum transport (AMT) lines as an aerodynamic functional diagnostic tool. The AMT lines are the ones whose tangents are given by the average angular momentum flux. The mathematical and physical properties of these AMT lines are exploited to study the generation, removal, and transport of angular momentum in turbomachinery components. We illustrate the concept by visualizing AMT lines in two relatively simple flows, namely, vaneless incompressible diffuser and von Karman flow (a model of centrifugal compressors). Next, we apply the proposed diagnostic tool to flow in a return channel. A return channel is a part of a multistage centrifugal compressor stage. Its principal function is to remove angular momentum. In this work, we apply the diagnostic tool of AMT lines to a Reynolds-averaged Navier Stokes (RANS) simulation and a wall-modeled large eddy simulation (LES) of flow in the return channel. We show that AMT lines give us insights into the AMT process that are otherwise not available with conventional visualization tools.

Detecting Multidimensional Pareto Fronts during the Optimization of a Return Channel within a Centrifugal Compressor

This paper explains the advantages of using big-data methods for evaluating numerical optimization. The investigation focuses on the performance potential of three-dimensional return channel vanes under realistic manufacturing constraints. Based on an analysis of an optimization database, the paper presents a systematic approach for analysis and setting up design guidelines. To this end, a validated numerical setup was developed on the basis of experiments, followed by a numerical optimization using genetic algorithms and artificial neural networks. The optimization database was analyzed with a dimension reduction method called t-SNE. This method enabled linking geometric design features with physical correlations and, finally, with the objective functions of the optimization. With the help of the detected correlations within the database, it has been possible to work out a method for deciding on the selection of a design on the Pareto front and to draw new relevant conclusions. The systematic use of big-data methods proposed enables a more penetrating insight to be gained into numerical optimization, which is more general and relevant than those gained by simply comparing a single optimized design with a reference design. An analysis of the Pareto front reveals that 0.6% efficiency can be exchanged for 20% more homogeneous outflow. The design of the vane profiles at hub and shroud works best using a front-loaded design for the hub side and an aft-loaded design for the shroud side, since this minimizes the blade-to-blade pressure gradient and, in turn, the secondary flow.

Aerodynamic Functional Diagnostics Based on Angular Momentum Transport Lines

In analogy with the classical concept of mass-flux-based streamlines, we define Angular Momentum Transport (AMT) lines as an aerodynamic functional diagnostic tool. The AMT lines are the ones whose tangents are given by the average angular momentum flux. The mathematical and physical properties of these AMT lines are exploited to study the generation, removal, and transport of angular momentum in turbomachinery components. We illustrate the concept by visualizing AMT lines in two relatively simple flows, namely, vaneless incompressible diffuser and von Karman flow (a model of centrifugal compressors). Next, we apply the proposed diagnostic tool to flow in a return channel. A return channel is a part of a multistage centrifugal compressor stage. Its principal function is to remove angular momentum. In this work, we apply the diagnostic tool of AMT lines to a Reynolds averaged Navier Stokes simulation (RANS) and a wall-modeled large eddy simulation (LES) of flow in the return channel. We show that AMT lines give us insights into the angular momentum transport process that are otherwise not available with conventional visualization tools.

The sponsorship performance cycle: longitudinal evidence of sponsors’ contribution to Formula One team achievement

Purpose A sponsorship performance cycle of business-to-business (B2B) exchange is conceptualized, where distinct types of resources are invested by sponsoring firms into sponsored properties and the competitive success of those properties enhances returns to sponsors. While the latter return channel in this cycle is well-documented, the former investment channel has remained opaque. Recognizing this empirical missing link, this paper aims to illuminate the investment channel through a longitudinal analysis. Design/methodology/approach Based on 50 years of Formula One (F1) team and sponsor alliances, this study models the effects of three different sponsorship categories on team performance in the annual F1 constructors’ championship. Findings The results demonstrate that each incremental sponsor offering performance-based resources is associated with four additional team points in the championship, controlling for factors such as past success and team experience. Conversely, sponsors offering access to financial or operational resources have no competitive impact. This performance-based sponsor effect is illustrated in models of the current and following seasons. Research limitations/implications In combination with related literature, this study substantiates a complete sponsorship performance cycle in the motorsports context. Practical implications The findings contribute an empirically-based strategy for sustainable sponsorship support that emphasizes acquisition of performance resources in the business-to-business exchange over operational or strictly financial alternatives. Originality/value While scholars have discerned that sponsors invest heterogeneous resources into sponsored properties, and the competitive success of those properties can enhance returns to sponsors, this study demonstrates that particular resources invested by sponsors are related to the property’s competitive success.

Flow Field Analysis and Feasibility Study of a Multistage Centrifugal Pump Designed for Low-Viscous Fluids

A multistage centrifugal pump is designed for pumping low-viscosity, highly volatile and flammable chemicals, including hydrocarbons, for high head requirements. The five-stage centrifugal pump consists of a double-suction impeller at the first stage followed by a twin volute. The impellers for stages two through five are single-suction impellers followed by diffuser vanes and return channel vanes. The analytical performance is calculated initially in the design stage by applying similarity laws to an existing scaled-down pump model designed for low flow rate applications. The proposed pump design is investigated using computational fluid dynamics tools to study its performance in design and off-design conditions for water as the base fluid. The design feasibility of the centrifugal pump is tested for other fluids, such as water at a high temperature and pressure, diesel and debutanized diesel. The pump design is found to be suitable for a variety of fluids and operating ranges. The losses in the pump are analyzed in each stage at the best efficiency point. The losses in efficiency and head are observed to be higher in the second stage than in other stages. The detailed flow behavior at the second stage is studied to identify the root cause of the losses. Design modifications are recommended to diminish the losses and improve the overall performance of the pump.

MODAL GRAIN SIZE EVOLUTION AS IT RELATES TO THE DREDGING AND PLACEMENT PROCESS - GALVESTON ISLAND, TEXAS

During the fall and winter of 2015, a beneficial-use of dredged material project taking material from the Galveston Entrance Channel and placing it on a severely eroded beach of Galveston Island was conducted. This material was estimated to have 38percent fines. This operation was conducted again in the fall of 2019 and monitored for estimation of the loss of fines, changes in compaction and color from the dredging source to the beach. The local community and state funded the incremental cost at approximately $8 a cubic yard in 2015, and $10.5 a cubic yard in 2019 to have this material pumped to the beach. The projects were closely monitored by the U.S. Army Corps of Engineers (USACE) Engineer Research and Development Center (ERDC) and the USACE Galveston District. The data from this placement project was used to calculate and better understand the loss of fines during the dredging and placement process as well as aid in the generation of an empirical formula to estimate the loss of fine sediments during dredging and beach placement. This formula takes into account: losses due to dredging equipment operations, slope of the effluent return channel at the beach, sediment settling velocity, and sorting parameter.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/VQ36upT2iQo

Network architecture of internet backhaul by DVB-RCS standards for shipborne and other mobile applications

In this paper is introduced a new Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) for the implementation of modern satellite Internet for shipborne, Vehicleborne and airborne mobile applications via Geostationary Erath Orbit (GEO) satellites. Mobile Satellite Internet aims at providing the next generation satellite broadcasting service through C, Ku and Ka-band DVB-S2 standard for Mobile Earth Stations (MES) via GEO satellite and Land Earth Stations (LES) to the ground or other mobile subscribers. It is de facto a mobile interactive broadcast satellite access system, which provides both TV broadcasting and high-speed Internet broadband based on DVB-S/DVB-RCS standards, Internet Protocol (IP) network, World Wide Web, IPTV, E-solutions and Communication, Navigation and Surveillance (CNS) systems to the passengers and crews onboard ships, land and aeronautical vehicles.