Purpose: The goal of this publication is to present a new laboratory methodology for simulation of industrial melting, solidification and heat treatment using the patented Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platform [10]. Two examples to demonstrate UMSA’s capabilities are presented for optimized heat treatment processes at the request of the North American automotive industry. Design/methodology/approach: The unique UMSA Platform was used to rapidly physically simulate very complex industrial heat treatment processes using stationary macro test samples and computer controlled heating and cooling source. Findings: The UMSA simulations proved to be very accurate in order to simulate the non-linear temperature/ time profile of the solidification process combined with the continuous heat treatment operation. Moreover, the complex industrial heat treatment process was successfully replicated for an 800g test sample and the targeted structural and mechanical properties were met. Research limitations/implications: Selected examples of the heat treatment have been presented for aluminum based alloys only. The current research addresses Mg and Ti based alloys and thermal processing under vacuum and inert/active environments. Practical implications: The presented methodology is capable of dissecting all processes and linking the cast component’s optimized performance with individual production steps. The technical capabilities of the UMSA Platform have been recognized and have already been applied by industrial partners. Originality/value: The simulation method that is presented here will greatly improve the ability of laboratory investigators to simulate and assess the effects of the heat treatment variables.
This paper presents the thermal analysis of a 60 kW switched reluctance motor (SRM) under peak operating conditions for traction application in a hybrid electric vehicle (HEV). The SRM has 24 stator poles and 16 rotor poles, and three-phases. Heat generation losses are determined using finite element analysis (FEA) electromagnetic simulations and these losses are input into a lumped parameter thermal network (LPTN) simulation representing the thermal circuit of the electric machine. A range of coolant inlet temperatures are input and the testing of various priority operating speed points leads to the analysis of the rise in temperature of different components within the machine. By applying temperature limiting constraints of the copper windings and the rotor lamination surface, the operating times with varying coolant inlet temperatures and operating speeds can be determined.
Hamiltonian encoding is a methodology for revealing the mechanism behind the dynamics governing controlled quantum systems. In this paper, following Mitra and Rabitz [Phys. Rev. A 67, 033407 (2003)], we define mechanism via pathways of eigenstates that describe the evolution of the system, where each pathway is associated with a complex-valued amplitude corresponding to a term in the Dyson series. The evolution of the system is determined by the constructive and destructive interference of these pathway amplitudes. Pathways with similar attributes can be grouped together into pathway classes. The amplitudes of pathway classes are computed by modulating the Hamiltonian matrix elements and decoding the subsequent evolution of the system rather than by direct computation of the individual terms in the Dyson series. The original implementation of Hamiltonian encoding was computationally intensive and became prohibitively expensive in large quantum systems. This paper presents two new encoding algorithms that calculate the amplitudes of pathway classes by using techniques from graph theory and algebraic topology to exploit patterns in the set of allowed transitions, greatly reducing the number of matrix elements that need to be modulated. These new algorithms provide an exponential decrease in both computation time and memory utilization with respect to the Hilbert space dimension of the system. To demonstrate the use of these techniques, they are applied to two illustrative state-to-state transition problems.
Traction motors play a critical role in electrified vehicles, including electric, hybrid electric, and plug-in hybrid electric vehicles. With high efficiency and power density, interior permanent magnet (IPM) synchronous machines have been employed in many commercialized electrified powertrains. In this paper, three different IPM rotor design configurations, which have been used in electrified powertrains from Toyota, Nissan, and General Motors, are comparatively investigated. Each topology is redesigned and improved to meet new design requirements based on the same constraints. The designed motors are then compared and comprehensively evaluated for motor performance, torque segregation, demagnetization, mechanical stress, and radial forces. The results suggest that the single V-shaped configuration achieves the best overall performance and is thus recommended as the best candidate.
We construct a relativistic quantum communication channel between two localized qubit systems, mediated by a relativistic quantum field, that can achieve the theoretical maximum for the quantum capacity in arbitrary curved spacetimes using the Unruh-DeWitt detector formalism. Using techniques from algebraic quantum field theory, we express the quantum capacity of the quantum communication channel purely in terms of the correlation functions of the field and the causal propagator for the wave equation. Consequently, the resulting quantum channel, and hence the quantum capacity, are by construction manifestly diffeomorphism-invariant, respect the causal structure of spacetime, and are independent of the details of the background geometry, topology, and the choice of Hilbert space (quasifree) representations of the field.
Purpose: Development of the understanding of the effect of the solidification rate with the alloy microstructures for the structural AM60B and the creep resistant AE44 Mg casting alloys. Design/methodology/approach: Tubular macro test samples of magnesium alloys AM60B and AE44 were melted and quenched at maximum instantaneous cooling rates ranging from -5°C/s to -500°C/s in the Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platform while recording the temperature-time traces. Such rapid cooling rates are typical in water-cooled dies used in high pressure die casting (HPDC). Characteristic reactions on these curves corresponding to the formation of individual phases during solidification were quantified based on cooling curve analysis combined with metallographic and micro-chemical analysis, with the aid of literature data. Findings: The results indicate that these phases, their size and location in the microstructure, their chemistry and their relative proportions all change in response to the increase in the cooling rate. The results are drastically different for the two alloy systems studied. Solidification of AM60B alloy yields small, equiaxed a-Mg rosettes whose size is mostly independent of the cooling rate. These rosettes nucleate heterogeneously on Al8Mn5 phases that are first to form, and are surrounded by the eutectic structure of Mg and Mg17Al12. In contrast, the AE44 has very large a-Mg grains at all cooling rates. These grains are filled with Al11RE3 platelets or dendrites. Results suggest that the Al11Re3 phase is completely ineffective in heterogeneous nucleation of a-Mg grains. Originality/value: In this research the authors significantly extended the thermal analysis methodology. The specific results obtained on the structural and creep-resistant Mg casting alloys are of significant value to the development of automotive light metal structures and power train components as well as further development of solidification codes for the commercial HPDC process.
