Numerical analysis of turbulent mixed convection air flow in inclined plane channel with k-ɛ type turbulence model

The Internal combustion engine is one of the widely used mechanical system. The primary aspect of all types of engines is the amount of power produced which, is affected by the complete combustion of a mixture of air and fuel. The objective of this present work is to outline the improved performance of single-cylinder Compression Ignition engine with the aid of geometrical modifications of Inlet manifold. The Study is performed on Kirlosakr CI engine. For modeling of engine assembly, CATIA V5 Software has been used. The Numerical simulations are performed with Ansys 14.5 and solver used as CFX. In this work, two different engine models such as Conventional valve and Modified valve with plate is being considered for CFD analysis. The simulation study of air flow motion with a valve lift of 4 mm, 6 mm and 8 mm is performed for both valve configurations. This numerical analysis aims to maximize the air velocity in the inlet valve with minimum turbulence which in turn improves the engine performance. The study is performed on the single cylinder four-stroke variable compression ratio diesel engines. In the present study, the air flow motion inside the intake manifold of an engine is simulated and investigations are performed by considering the six conditions of the intake valve. The results obtained acts as a basis for further investigation of a variety of valve geometry.

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The Simulation of Natural Ventilation of Buildings With Different Location of Windows/Openings

Volume 6B: Energy ◽

10.1115/imece2015-51168 ◽

2015 ◽

Author(s):

A. Idris ◽

B. P. Huynh ◽

Z. Abdullah

Keyword(s):

Air Quality ◽

Flow Pattern ◽

Turbulence Model ◽

Natural Ventilation ◽

Air Flow ◽

Building Design ◽

Building Envelope ◽

Navier Stokes ◽

Computational Domain ◽

Numerical Predictions

Ventilation is a process of changing air in an enclosed space. Air should continuously be withdrawn and replaced by fresh air from a clean external source to maintain internal good air quality, which may referred to air quality within and around the building structures. In natural ventilation the air flow is due through cracks in the building envelope or purposely installed openings. Its can save significant amount of fossil fuel based energy by reducing the needs for mechanical ventilation and air conditioning. Numerical predictions of air velocities and the flow patterns inside the building are determined. To achieve optimum efficiency of natural ventilation, the building design should start from the climatic conditions and orography of the construction to ensure the building permeability to the outside airflow to absorb heat from indoors to reduce temperatures. Effective ventilation in a building will affects the occupant health and productivity. In this work, computational simulation is performed on a real-sized box-room with dimensions 5 m × 5 m × 5 m. Single-sided ventilation is considered whereby openings are located only on the same wall. Two opening of the total area 4 m2 are differently arranged, resulting in 16 configurations to be investigated. A logarithmic wind profile upwind of the building is employed. A commercial Computational Fluid Dynamics (CFD) software package CFD-ACE of ESI group is used. A Reynolds Average Navier Stokes (RANS) turbulence model & LES turbulence model are used to predict the air’s flow rate and air flow pattern. The governing equations for large eddy motion were obtained by filtering the Navier-Stokes and continuity equations. The computational domain was constructed had a height of 4H, width of 9H and length of 13H (H=5m), sufficiently large to avoid disturbance of air flow around the building. From the overall results, the lowest and the highest ventilation rates were obtained with windward opening and leeward opening respectively. The location and arrangement of opening affects ventilation and air flow pattern.

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Numerical Analysis on Thermal Energy Storage Device With Finned Copper Tube for an Indirect Type Solar Drying System

Journal of Solar Energy Engineering ◽

10.1115/1.4039273 ◽

2018 ◽

Vol 140 (3) ◽

Cited By ~ 5

Author(s):

Satyapal Yadav ◽

V. P. Chandramohan

Keyword(s):

Energy Storage ◽

Numerical Analysis ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Air Flow ◽

Storage Device ◽

Energy Storage Device ◽

Solar Drying ◽

Solar Dryer ◽

Air Flow Velocity

Solar dryer with thermal energy storage device is an essential topic for food drying applications in industries. In this work, a two-dimensional (2D) numerical model is developed for the application of solar drying of agricultural products in an indirect type solar dryer. The phase-change material (PCM) used in this work is paraffin wax. The study has been performed on a single set of concentric tube which consists of a finned inner copper tube for air flow and an outer plastic tube for PCM material. The practical domain is modeled using ANSYS, and computer simulations were performed using ANSYS fluent 2015. The air velocity and temperature chosen for this study are based on the observation of indirect type solar dryer experimental setup. From this numerical analysis, the temperature distribution, melting, and solidification fraction of PCM are estimated at different air flow velocities, time, and inlet temperature of air. It is concluded that the drying operation can be performed up to 10.00 p.m. as the PCM transfers heat to inlet air up to 10.00 p.m. and before it got charged up to 3.00 p.m. because of solar radiation. The maximum outlet temperature is 341.62 K (68.62 °C) which is suitable for food drying applications. Higher air flow velocity enhances quick melting of PCM during charging time and quick cooling during recharging of inlet air; therefore, higher air flow velocity is not preferred for food drying during cooling of PCM.

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Evaluation and Optimisation of Processes Time for the Hot Air Oven Containing Sleeves

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.38109 ◽

2021 ◽

Vol 9 (11) ◽

pp. 404-410

Author(s):

Bandaru Nithin Kumar Varma

Keyword(s):

Heat Transfer ◽

Mixed Convection ◽

Epoxy Resin ◽

Latent Heat ◽

Air Flow ◽

Whole Process ◽

Hot Air

Abstract: The Hot air producing Oven is used to heat the sleeves which are used as raiser in casting purpose. The sleeves that are being manufactured are made of epoxy resin which consists of approximately 75% water and 25% mineral mix before heating and once the processes are complete i.e. the sleeves getting heated in the oven the product would turn into 35% water + 65% mix. The whole process would estimate the time around 4.5 hours. The first 2.5 hours the water is being removed from the sleeves in form of latent heat vaporization. The next 2 hours is use as the time for curing the them because of the flow of hot air through the sleeves. The processes time is evaluated keeping in mind that the heat transfer is happening in mixed convection. As they are placed vertically to the direction of air flow. The amount of heat transfer in terms of energy is evaluated for 4.5 hours in actual practise. The energy which is utilised in 4.5 hours is found and the same amount is consumed in 2.5 hours which is a solution solved theoretically by considering datum values. Keywords: epoxy resin, sleeves, latent heat, heat transfer, mixed convection.

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