Simplified Algorithm Model for Explosion Shockwave Load in the Cabin

In order to obtain the shockwave load simplified algorithm model for the semiarmored projectile internal explosion in the cabin, this research made use of AUTODYN to provide a numerical modeling method for explosion in the cabin and verified the accuracy of the method via the experiment. Internal explosion simulation calculation was conducted on the operating condition numerical model with different cabin structural dimensions and different explosive loads. The cabin internal explosion space was divided into the noncorner central area, near-wall area, two-sided corner area, and three-sided corner area. Through regression of the abovementioned calculation results, an engineering model to calculate the shockwave load was obtained. It is hoped that the model can offer some references to the antiexplosion design for the ship cabin and for damage assessment of the internal explosion.

Experimental results of wake steering using fixed angles

In this article, the authors present a test of wake steering at a commercial wind farm. A single fixed yaw offset, rather than an optimized offset schedule, is alternately applied to an upstream wind turbine, and the effect on downstream turbines is analyzed. This experimental design allows for comparison with engineering wake models independent of the controller's ability to track a varying offset and correctly measure wind direction. Additionally, by applying the same offset in beneficial and detrimental conditions, we are able to collect important data for assessing second-order wake model predictions. Results of the article from collected data show good agreement with the FLOw Redirection and Induction in Steady State (FLORIS) engineering model and offer support for the asymmetry of wake steering predicted by newer models, such as the Gauss–curl hybrid model.

Mô hình số kỹ thuật cho cầu đúc sẵn sử dụng trong thiết kế định hướng chế tạo và lắp dựng

Xây dựng cầu sử dụng cấu kiện đúc sẵn đang là xu hướng công nghệ chủ đạo để nâng cao năng suất, chất lượng và hiệu quả sử dụng chi phí. Từ giai đoạn thiết kế đến các giai đoạn sản xuất và lắp dựng, việc chuyển giao thông tin theo các cấu kiện đúc sẵn là một thách thức kỹ thuật lớn do hiệu ứng silo cản trở việc trao đổi thông tin giữa các giai đoạn. Nghiên cứu này xem xét tác dụng của chuyển đổi số, một xu hướng sử dụng mô hình kỹ thuật số kết hợp với các tri thức khác trong các dự án xây dựng đối với vấn đề này. Mô hình số kỹ thuật (Digital Engineering Model - DEM) cho cầu sử dụng cấu kiện đúc sẵn đã được nghiên cứu đề xuất để kết nối các dòng chảy kỹ thuật từ mô hình kỹ thuật số cho thiết kế, đến mô hình số cho chế tạo và lắp dựng. Để minh họa, bài báo trình bày kết quả thử nghiệm áp dụng Phương pháp Thiết kế định hướng Chế tạo và Lắp dựng (Design for Manufacturing and Assembly - DfMA) và BIM (Building Information Modelling) cho giai đoạn thiết kế cầu sử dụng cấu kiện đúc sẵn, cho một trụ cầu tiền chế. Kết quả thử nghiệm chứng minh các mô hình này giúp tăng tính hiệu quả trong việc phối hợp và giao tiếp giữa các bên hữu quan dự án.

Analysis of the engineering mathematical model of the physical properties of a three-layer hydroacoustic screen with anisotropic components

A numerical-analytical technique for analyzing the physical effects of the formation of fields of hydroacoustic waves in the area in front of a flat three-layer hydroacoustic screen and in the space behind the screen at normal incidence of a stationary hydroacoustic wave on it is presented. The engineering model of the screen uses the assumption that its components are made of anisotropic functional-gradient materials with exponential inhomogeneity in thickness, and thin, absolutely flexible, inextensible coatings can be applied to the outer and contact surfaces of the layers. The technique is based on the analytical integration of the equations of wave deformation of the screen components and obtaining complex amplitude characteristics for the reflected and generated hydroacoustic waves behind the screen when solving a system of algebraic equations with a functional matrix, which follows from the boundary conditions for the investigated problem. Parametric descriptions for the characteristics of the investigated physical fields are obtained and examples of numerical analysis of the considered engineering model are presented.

Detection of Low-Energy X-rays Using YSO Scintillation Crystal Arrays for GRB Experiments

We developed an X-ray detector using 36 arrays, each consisting of a 64-pixellated yttrium oxyorthosilicate (YSO) scintillation crystal and a 64-channel multi-anode photomultiplier tube. The X-ray detector was designed to detect X-rays with energies lower than 10 keV, primarily with the aim of localizing gamma-ray bursts (GRBs). YSO crystals have no intrinsic background, which is advantageous for increasing low-energy sensitivity. The fabricated detector was integrated into UBAT, the payload of the Ultra-Fast Flash Observatory (UFFO)/Lomonosov for GRB observation. The UFFO was successfully operated in space in a low-Earth orbit. In this paper, we present the responses of the X-ray detector of the UBAT engineering model identical to the flight model, using 241Am and 55Fe radioactive sources and an Amptek X-ray tube. We found that the X-ray detector can measure energies lower than 5 keV. As such, we expect YSO crystals to be good candidates for the X-ray detector materials for future GRB missions.

Pre-flight qualification tests of the Mini-EUSO telescope engineering model

Mini-EUSO is part of the JEM-EUSO program and operates on board the International Space Station (ISS). It is a UV-telescope with single-photon counting capability looking at nighttime downwards to the Earth through a nadir-facing UV-transparent window. As part of the pre-flight tests, the Mini-EUSO engineering model, a telescope with 1/9 of the original focal surface and a lens of 2.5 cm diameter, has been built and tested. Tests of the Mini-EUSO engineering model have been made in laboratory and in open-sky conditions. Laboratory tests have been performed at the TurLab facility, located at the Physics Department of the University of Turin, equipped with a rotating tank containing different types of materials and light sources. In this way, the configuration for the observation of the Earth from space was emulated, including the Mini-EUSO trigger schemes. In addition to the qualification and calibration tests, the Mini-EUSO engineering model has also been used to evaluate the possibility of using a JEM-EUSO-type detector for applications such as observation of space debris. Furthermore, observations in open-sky conditions allowed the studies of natural light sources such as stars, meteors, planets, and artificial light sources such as airplanes, satellites reflecting the sunlight, and city lights. Most of these targets could be detected also with Mini-EUSO. In this paper, the tests in laboratory and in open-sky conditions are reported, as well as the obtained results. In addition, the contribution that such tests provided to foresee and improve the performance of Mini-EUSO on board the ISS is discussed.