Tipparthi, VK (2017) Design and Development of a Dual Flow System for Fluid Delivery in Grinding Application. Doctoral thesis, Liverpool John Moores University.

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Abstract

The main aim of this research work is investigate into coolant delivery system in order to develop a radically new generation of parametric multi-purpose nozzle system, which incorporate a dual/triple flow coupled system to deliver a low volume, low pressure fluid for both conventional and MQL coolant applications in grinding process with step-up pressure. The investigation aimed to show through design, simulation and experimental study the possibility of a step change in the amount of cutting fluid used in grinding by combining positive aspects of MQL and conventional nozzles, to come up with high performance universal nozzle and draw its characteristics via measurement in terms of jet velocity, trends of coherence length, and fluid flow patterns. To achieve this, aim a new concept termed ‘Nested Nozzles’ was designed and implemented giving birth to a new approach to fluid delivery that is “Dual/Triple Fluid Configurable Delivery”. It is demonstrated here for the first time that by nesting a nozzle in the cavity of another one can step up the inlet pressure by a factor, thus eliminating the need of high pressure supply. The nested nozzle acts as a flow conditioner creating a laminar flow; also in addition the flow through this nested nozzle accelerates the primary flow, thus inducing a stepping effect in the velocity. Besides flow conditioning, pressure and velocity step-up effect, the nested nozzle offers the supply of one or two fluids either alone or in combination. This, together with the main nozzle allows for dual/triple fluid delivery and their combination The relationship between the flows and the pressures in the main and nested nozzles was investigated and an optimized design emerged with a modular configurable multi-purpose nozzle. Here with a single nozzle one could apply conventional flood cooling with reduced fluid requirement, MQL or multiple fluid deliveries. The nozzle exit aperture can be flexibly configured based on the application need from 0.3 mm up to 0.7 mm. A wide range of simulations was undertaken in SolidWorks CFD and ANSYS CFX software packages. Air, oil, water and their mixtures were used as cooling media. The results revealed the flow behaviour intra-nozzle and externally where the fluid exited the nozzle aperture. The jet coherency length was estimated from these simulations along with velocity profiles. An attempt was made in simulating Wheel-Nozzle-Workpiece subsystem to show the interaction of the three elements. A test rig was set up using a surface grinding machine, which was modified and instrumented with 3-axis digital readout, data acquisition system with LabVIEW software and sensors with Pitot tube. The results of the measurement reveal fundamentally new behaviour of the fluid that has not recorded earlier. In a three-layered measurement across nozzle aperture and along the stream, it was found that the fluid velocity after exiting the nozzle increased from top layer to bottom layer, however decreased monotony down the stream. A conical core of fluid keeping original exit velocity was observed in the centre of the jet. These two key finding gave an indication as to where to position the workpiece (grinding contact zone) and the orientation of the nozzle relative to the cutting zone. It is therefore suggested that the bottom third of the jet be directed into the contact zone whilst the top two third be aimed at the wheel. As this work has only answered some questions in fluid application, it has conversely open numerous questions yet to be investigated, therefore, recommendations for further studies are given along with some initial ideas and directions.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	General Engineering Research Institute
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TJ Mechanical engineering and machinery
Divisions:	Engineering
Date Deposited:	09 May 2017 10:17
Last Modified:	29 Nov 2022 16:28
DOI or ID number:	10.24377/LJMU.t.00006362
Supervisors:	Batako, ADL
URI:	https://researchonline.ljmu.ac.uk/id/eprint/6362

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