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1

Wpływ zastosowania muld chłonnych oraz powierzchni przepuszczalnych na ograniczenie spływu powierzchniowego

Suchanek-Gabzdyl Ewa

Instal

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2023

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nr 12

140--144

PL

Woda opadowa jest głównym źródłem zasobów wodnych, które umożliwiają odnawianie się wód powierzchniowych i podziemnych. Ze względu na niezrównoważony rozwój obszarów zurbanizowanych i wiejskich, opady zaczynają być postrzegane jako źródło zagrożenia. Ten stan prowadzi do pojawienia się nowego zjawiska, jakim są powodzie miejskie (ang. urbanflood). Obszary miejskie, które jeszcze kilkadziesiąt lat temu nie miały problemów z odprowadzaniem wód opadowych, obecnie po wystąpieniu intensywnych opadów atmosferycznych, zamieniają się w zalane tereny. Drugim istotnym aspektem są zmiany klimatyczne. W ostatnich latach liczne anomalie pogodowe, takie jak ulewny deszcz, prowadzą do powstawania nagłych powodzi miejskich (ang. flashflood), które powodują nagłe zalanie niższych obszarów, często tworząc fale wezbraniowe. Aby poradzić sobie z tymi problemami, coraz częściej w miastach stosuje się urządzenia do retencji i infiltracji wód opadowych. Działania takie nie wymagają przebudowy istniejących już kanałów burzowych, a realizowane są poprzez tworzenie ogrodów deszczowych, muld chłonnych czy powierzchni przepuszczalnych. Dodatkowo, zwiększa się zasobność wód podziemnych, urozmaicając krajobraz i estetykę miast, co prowadzi do poprawy mikroklimatu i warunków życia mieszkańców.

EN

Rainwater is the main component of water resources, which ensures the replenishment of surface and underground waters. Due to the unsustainable development of urban and rural areas, precipitation is beginning to be perceived as a source of threat. This situation leads to the emergence of a new phenomenon known as urban flooding. Urban areas that had no issues with rainwater drainage several decades ago now transform into floodplains after heavy rainfall. The second important aspect is climate change. The occurrence of numerous weather anomalies, such as torrential rain, in recent years has resulted in the formation of flash floods in cities, causing sudden inundation of lower-lying areas, often creating a surge wave. To address these problems, rainwater retention and infiltration devices are increasingly being employed in cities. Such measures do not require the reconstruction of existing storm drains and can be implemented through the creation of rain gardens, absorbent mounds, or permeable surfaces, for example. Furthermore, these initiatives enhance groundwater resources and enrich the landscape and aesthetics of cities, leading to an improved microclimate and better living conditions for the urban population.

2

Analysis of a chemically reactive MHD flow with heat and mass transfer over a permeable surface

Fenuga O. J., Aroloye S. J., Popoola A. O.

International Journal of Applied Mechanics and Engineering

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2019

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Vol. 24, no. 1

53--66

EN

This paper investigates a chemically reactive Magnetohydrodynamics fluid flow with heat and mass transfer over a permeable surface taking into consideration the buoyancy force, injection/suction, heat source/sink and thermal radiation. The governing momentum, energy and concentration balance equations are transformed into a set of ordinary differential equations by method of similarity transformation and solved numerically by Runge- Kutta method based on Shooting technique. The influence of various pertinent parameters on the velocity, temperature, concentration fields are discussed graphically. Comparison of this work with previously published works on special cases of the problem was carried out and the results are in excellent agreement. Results also show that the thermo physical parameters in the momentum boundary layer equations increase the skin friction coefficient but decrease the momentum boundary layer. Fluid suction/injection and Prandtl number increase the rate of heat transfer. The order of chemical reaction is quite significant and there is a faster rate of mass transfer when the reaction rate and Schmidt number are increased.

3

Dispersion of waves in coated poroelastic circular cylinders

Shah S. A., Tajuddin M.

International Journal of Applied Mechanics and Engineering

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2012

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Vol. 17, no. 1

213-231

EN

The phenomenon of crack initiation due to dynamic contact loading is referred to as fretting fatigue. This situation is commonly encountered in mechanical couplings subjected to vibration. Whenever a material has good mechanical properties but poor fretting resistance it is advantageous to provide a layer of material having good fretting resistance instead of changing the entire material. This extra layer of material can be provided by coating or by any other surface treatment methods. Wave propagation in coated poroelastic cylinders of infinite extent is investigated employing Biot's theory. The coated poroelastic cylinder consists of two poroelastic cylinders of different poroelastic materials bonded at the curved surface such that the liquids in the poroelastic materials are immiscible. Frequency equations of coated poroelastic cylinders are derived both for pervious and impervious surfaces. Let the infinite coated poroelastic cylinder be homogeneous and isotropic and the outer boundary is free from stress. At the interface of the core and coating, the stresses and displacements are continuous. For motions having infinite wavelength or when the wavenumber is zero, the axial shear and radial modes of the coated poroelastic cylinder are uncoupled each for a pervious and an impervious surface. The frequency equation of axial shear vibrations is same for pervious and impervious surfaces. Non-dimensional phase velocity for propagating modes is computed as a function of propagation constant in the absence of dissipation. The results are presented graphically for two types of coated poroelastic cylinders and then discussed.

4

Torsional vibrations of poroelastic prolate spheroids

Shah S. A., Tajuddin M.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 2

521-529

EN

In this paper, propagation of torsional vibrations in poroelastic prolate spheroids is investigated employing Biot's theory. Frequency equations of torsional vibrations are obtained for a poroelastic solid prolate spheroid and thick walled prolate spheroidal shells. Frequency equations are the same for pervious and impervious surfaces. Results of previous investigations are shown as a particular case of the present study.