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A Comparative Numerical and Experimental Study of Light Weight Materials for Neutralizing Explosive Reactive Armour

Naeem Khalid, Hussain Arshad, Malik Abdul Qadeer, Abbas Shakeel, Ahmad Iftikhar, Farrukh Sarah

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 2

271--286

EN

Explosive reactive armour (ERA) consists of an explosive sandwiched between two metal plates fitted on armoured vehicles to enhance their protection. To defeat an ERA mounted vehicle, its ERA must be neutralized first. A precursor fitted in a TANDEM warhead is used for this purpose in two modes. One is to detonate the ERA and the other is without detonation. This paper presents work performed on the ability of light-weight materials to neutralize the Kontakt-5 ERA without detonation. The precursor performing in this manner is known as a non-initiating precursor (NIP). Eight experiments were performed with aluminium, Teflon® and perspex as liners, against Kontakt-5 ERAs at about 90º and 30º inclination. In five of these experiments, the ERA did not detonate, however in three experiments it did detonated. In all of the experiments the precursor over-performed, producing a prominent hole in the target larger than that predicted by simulation. The over-performance was balanced by decreasing the angle of attack. These experiments demonstrated that an NIP depends strongly upon the ERA as well as on the angle of attack. The overall conclusion from this work is that an NIP is a promising technique to defeat a specific ERA without detonation.

2

Extraction and application of natural pigments for fabrication of green dye-sensitized solar cells

Hosseinnezhad M., Rouhani S., Gharanjig K.

Opto-Electronics Review

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2018

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Vol. 26, No. 2

165--171

EN

Four dye-sensitized solar cell devices are designed and fabricated based on natural dyes extracted from Celosia Cristata, Saffron, Cynoglossum, and eggplant peel, as photosensitizers. The UV–vis technique has been served to determine maximum absorption of natural extract and pre-dyed photoanode. The Fourier transform infrared (FT-IR) was employed to cover the presence of functional groups. The cyclic voltammetry method has been employed to assess the possibility of charge transfer from dried natural dyes to the photoelectrode. The performance of natural-based dye-sensitized solar cells is determined subsequently. The highest power conversion efficiency was ca. 1.38%, which belonged to Celosia Cristata extract. The devices were examined for higher efficiencies, individually, co-sensitized arrangement and/or in tandem with each other.

3

Zrobotyzowane spawanie czerpaków koparek

Idziak E., Szyszka R., Siennicki A., Turek B.

Górnictwo i Geoinżynieria

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2007

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R. 31, z. 2

253-265

PL

Czerpaki koparek są elementami ulegającymi szybkiemu zużyciu. Każdy czerpak przed ponownym zamontowaniu na koparce podlega regeneracji. Na zrobotyzowanym stanowisku spawalniczym w czasie procesu regeneracji operacje wycięcia zużytych części czerpaka, napawanie oraz spawanie wykonywane są automatycznie. Jest to możliwe, ponieważ stanowisko składa się z robota serii ROMAT 320, pozycjonera przechylno-obrotowego o nośności 75000 N oraz urządzeń spawalniczych wykonujących następujące procesy: - wysokowydajne spawanie MAG/MIG metodą TANDEM, - cięcie tlenem, - cięcie plazmowe, - napawanie drutami rdzeniowymi samoosłonowymi. Wykonanie powtarzalnych operacji w procesie regeneracji czerpaków na zrobotyzowanym stanowisku spowodowało zwiększenie wydajności pracy, poprawę jakości oraz wyeliminowanie najbardziej uciążliwych i szkodliwych dla zdrowia pracowników operacji wykonywanych dotychczas ręcznie.

EN

Excavator buckets are fast moving elements. Each bucket is subject for rebuilding before renewed assembly on the excavator. On the robotized welding stand, during rebuilding process, operations of bucket wear parts cutting out, facing by welding, and welding are automatically executed. This is possible since this stand is composed of ROMAT 320 series robot, tilling-rotary positioner witch load capacity 75000 N and welding installation currying following processes: - high-duty MAG-MIG TANDEM method welding, - oxy cutting, - plasma cutting, - facing by core self-guard wires. Reproducible operations execution during bucket rebuilding process with robotized stand caused more efficiency increasing, quality improvement and most noxious and harmful operations elimination for workers health, which were manually by them executed as yet.

4

Interference of unsteady phenomena in flow around bluff-bodies arrangement

Jarża A., Gnatowska R.

Inżynieria Chemiczna i Procesowa

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2006

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T. 27, z. 3/1

721-735

EN

The paper contains an analysis of unsteady phenomena resulting from the interference of the wake flow around the system of sharp-edged bluff-bodies in a uniform oncoming stream. The configuration of two parallel square cross-section prismatic bodies, arranged in a tandem is considered for the 2D case. The program of the study consists of wind-tunnel experiments and numerical simulation performed with the use of phase-averaged form of k-. turbulence model in a RNG version. The original contribution of the paper is the recognition of dynamic properties of vortex structures around interfering bluff-bodies in a tandem arrangement. The numerical simulation provided necessary data to conclude that different flow regimes around interfering bodies are due to the interaction between the separated shear layer from the first obstacle and the reattachment and impingement pattern on the faces of downstream body. The obtained results revealed that time characteristics both of the velocity and pressure field can be grouped in separate classes based on the body spacing, according to observed flow regimes (single-body, bi-stable, critical, quasi-isolated).

PL

Przeprowadzono analizę eksperymentalno-numeryczną aerodynamicznej interakcji obiektów usytuowanych w układzie tandemu, której celem było stwierdzenie, w jakim stopniu parametry geometryczne układu wpływają na zmienną w czasie strukturę opływu obiektów i zachodzące wokół nich procesy interferencji aerodynamicznej. Analiza objęła określenie zależności między nieustalonym polem prędkości wokół badanej konfiguracji a dynamiką obciążeń ciśnieniowych. W szczególny sposób skupiono się na roli oscylacji przepływu w otoczeniu elementów układu jako na podstawowym zjawisku odpowiedzialnym za formowanie się stanów dynamicznych towarzyszących ich interferencji.