The Effect of Particle Feed Rate on the Plastic Media Blast Jet

1992 ◽  
Vol 114 (4) ◽  
pp. 435-440
Author(s):  
M. J. McIntosh
Keyword(s):  
Kinetic Energy ◽  
Feed Rate ◽  
Momentum Balance ◽  
Work Piece ◽  
Military Aircraft ◽  
Energy Delivery ◽  
Particle Feed Rate ◽  
Paint Removal ◽  
Semi Empirical ◽  
Plastic Media

Paint removal from military aircraft is often done by plastic media blasting (PMB): the use of plastic grit in a conventional blast jet. However, there is some concern that PMB will cause damage. To help in evaluating this possibility, a “time of flight” meter is used to measure particle velocity in the jet, as a function of air pressure, distance from the nozzle, and particle feed rate, F. Using the data and a momentum balance, a semi-empirical model relating these variables is developed and used for analysis of the effect of F on the intensity of kinetic energy delivery, E, to a work piece. The analysis shows that F has several important effects on E. These methods and results will be useful for damage studies and in production work.

System Identification of the High Performance Drilling Process for Network-Based Control

2007 ◽  
Author(s):  
Rau´l M. del Toro ◽  
Michael C. Schmittdiel ◽  
Rodolfo E. Haber-Guerra ◽  
Rodolfo Haber-Haber
Keyword(s):  
Dynamic Behavior ◽  
Feed Rate ◽  
Network Architecture ◽  
High Performance ◽  
Control Strategies ◽  
Input Function ◽  
Resultant Force ◽  
Work Piece ◽  
Drilling Process ◽  
Force System

A simple, fast, network-based experimental procedure for identifying the dynamics of the high-performance drilling (HPD) process is proposed and successfully applied. This identification technique utilizes a single-input (feed rate), single-output (resultant force) system with a dual step input function. The model contains the delays of both the network architecture (a PROFIBUS type network) and the dead time related with the plant dynamic itself. Classical identification techniques are used to obtain first order, second order, and third order models on the basis of the recorded input/output data. The developed models relate the dynamic behavior of resultant force versus commanded feed rate in HPD. Model validation is performed through error-based performance indices and correlation analyses. Experimental verification is performed using two different work piece materials. The models match perfectly with real-time force behavior in drilling operations and are easily integrated with many control strategies. Furthermore, these results demonstrate that the HPD process is somewhat non-linear with a remarkable difference in gain due to work piece material; however, the dynamic behavior does not change significantly.

Modeling of Material Removal Mechanism in Micro Electric Discharge Milling of Ti-6Al-4V

2014 ◽  
Vol 592-594 ◽  
pp. 516-520 ◽  
Author(s):  
Basil Kuriachen ◽  
Jose Mathew
Keyword(s):  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Milling Process ◽  
Work Piece ◽  
Machining Parameters ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Electric Discharge Milling

Micro EDM milling process is accruing a lot of importance in micro fabrication of difficult to machine materials. Any complex shape can be generated with the help of the controlled cylindrical tool in the pre determined path. Due to the complex material removal mechanism on the tool and the work piece, a detailed parametric study is required. In this study, the influence of various process parameters on material removal mechanism is investigated. Experiments were planned as per Response Surface Methodology (RSM) – Box Behnken design and performed under different cutting conditions of gap voltage, capacitance, electrode rotation speed and feed rate. Analysis of variance (ANOVA) was employed to identify the level of importance of machining parameters on the material removal rate. Maximum material removal rate was obtained at Voltage (115V), Capacitance (0.4μF), Electrode rotational Speed (1000rpm), and Feed rate (18mm/min). In addition, a mathematical model is created to predict the material removal

A Parametric Optimization on Cutting Force during Laser Assisted Machining of Inconel 718 Alloy

2015 ◽  
Vol 787 ◽  
pp. 460-464 ◽  
Author(s):  
M. Vignesh ◽  
K. Venkatesan ◽  
R. Ramanujam ◽  
P. Kuppan
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Inconel 718 ◽  
Laser Power ◽  
Laser Cutting ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Work Piece ◽  
Conventional Machining

Inconel 718, a nickel based alloys, addressed as difficult to cut material because of hard carbide particle, hardness, work hardening and low thermal conductivity. Improving the machinability characteristics of nickel based alloys is a major anxiety in aircraft, space vehicle and other manufacturing fields. This paper presents an experimental investigation in Laser assisted turning of Inconel 718 to determine the effects of laser cutting parameters on cutting temperature and cutting forces. This nickel alloy has a material hardness at 48 HRC and machined with TICN/Al2O3/TiN tool. This is employed for the manufacture of helicopter rotor blades and cryogenic storage tanks. The experiments were conducted at One-Factor-at-a-Time.The effects of laser cutting parameters, namely cutting speed, feed rate, laser power and laser to work piece angle, on the cutting temperature and cutting force components, are critically analysed and the results are compared with unassisted machining of this alloy. The experiments are conducted by varying the cutting speed at three levels (50, 75, 100 m/min), feed rate (0.05, 0.075 0.1 mm/rev), laser power (1.25 kW, 1.5 kW, 1.75 kW) and at two level laser to work piece angle (60, 75°). At the optimal parametric combinationof laser power 1.5 kW with cutting speed of 75m/min, feed rate of 0.075 mm/min and laser to work piece angle 60°, the benefit of LAM was shown by 18%, 25% and 24% decrease in feed force (Fx), thrust force (Fy) and cutting force (Fz) as compared to those of the conventional machining. Examination of the machined surface hardness profiles showed no change under LAM and conventional machining.

scholarly journals WAVES OVERTOPPING A WIDE-CRESTED DIKE

2011 ◽  
Vol 1 (32) ◽  
pp. 7 ◽  
Author(s):  
Toon Verwaest ◽  
Philippe Vanpoucke ◽  
Marc Willems ◽  
Tom De Mulder
Keyword(s):  
Theoretical Model ◽  
Energy Balance ◽  
Kinetic Energy ◽  
Scale Model ◽  
Coastal Protection ◽  
Model Concept ◽  
Wave Overtopping ◽  
Model Research ◽  
Physical Scale ◽  
Semi Empirical

If a coastal dike has a crest width of more than say a few meters, then wave overtopping will be significantly reduced due to the crest width, because kinetic energy can be dissipated on the crest and water on the crest can flow back towards the seaside. In coastal towns built on dune belts often a wide-crested coastal dike was constructed as both coastal protection and sea promenade. However, quantifying the effect of such a wide crest on wave overtopping is not straightforward because no empirical overtopping formulas are given in literature for this kind of configuration. Therefore physical scale model research was carried out. Also a simplified theoretical model concept was used based on an energy balance formulation of a single overtopping wave. Combining the scale model measurements with the theoretical model, a semi-empirical formula was developed and calibrated.

scholarly journals Modelling of snow entrainment and deposition in powder-snow avalanches

1998 ◽  
Vol 26 ◽  
pp. 253-258 ◽  
Author(s):  
Dieter Issler
Keyword(s):  
Kinetic Energy ◽  
Three Dimensional ◽  
Momentum Balance ◽  
Model Parameters ◽  
Momentum Exchange ◽  
Erosion And Deposition ◽  
Practical Applications ◽  
Suspension Layer ◽  
Dense Flow ◽  
Avalanche Formation

Following Norem’s description of powder-snow avalanche formation and structure, we propose a mathematical model that consists of a suspension layer and a so-called saltation layer. The latter is only a few meters deep and is modelled by depth-averaged mass and momentum balances. In the suspension layer, the mass and momentum balance equations for the mixture are supplemented by the snow mass balance and the transport equations for turbulent kinetic energy and dissipation. Mass and momentum exchange between the two layers is determined by particle settling, turbulent diffusion against the concentration gradient and aerodynamic shear forces. The net erosion or deposition rate is a function of the kinetic energy of the impacting particles. The saltation layer reacts on the suspension layer in that saltating particles extract momentum from the air flow. The preliminary estimates of the model parameters can be refined by means of saltation-trajectory simulations. Three-dimensional simulations with a simplified model have clearly shown the importance of snow erosion and deposition in practical applications. This approach is well suited for coupling to a dense-flow avalanche model.

FEM Simulation of Machining AISI 1045 Steel Using Driven Rotary Tool

2015 ◽  
Vol 758 ◽  
pp. 77-82 ◽  
Author(s):  
Yanuar Burhannudin ◽  
Suryadiwansa Harun ◽  
Gusri Akhyar Ibrahim
Keyword(s):  
Feed Rate ◽  
Fem Simulation ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Work Piece ◽  
Rotary Tool ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
Simulation Results ◽  
1045 Steel

This study investigates the influences of driven rotary tool (DRT) on temperatures and forces when turning AISI 1045 steel. A set of cutting conditions was used in FE simulations to predict cutting force, stresses and temperatures developed at around the edge of tool. The material cutting speed ranges were set between 20 and 250 m min-1. The rotary tool speed were 0 and 100 rpm.. The feed rate and the depth of cut were set constant. Simulation results provided the predicted cutting distribution of temperatures and stresses at the chip and work piece.

Do Eddies Play a Role in the Momentum Balance of the Leeuwin Current?

2005 ◽  
Vol 35 (6) ◽  
pp. 964-975 ◽  
Author(s):  
Ming Feng ◽  
Susan Wijffels ◽  
Stuart Godfrey ◽  
Gary Meyers
Keyword(s):  
Kinetic Energy ◽  
Pressure Gradient ◽  
Reynolds Stress ◽  
Wind Stress ◽  
Mesoscale Eddies ◽  
Eddy Kinetic Energy ◽  
Momentum Balance ◽  
Gradient Force ◽  
Leeuwin Current ◽  
Eastern Boundary

Abstract The Leeuwin Current is a poleward-flowing eastern boundary current off the western Australian coast, and alongshore momentum balance in the current has been hypothesized to comprise a southward pressure gradient force balanced by northward wind and bottom stresses. This alongshore momentum balance is revisited using a high-resolution upper-ocean climatology to determine the alongshore pressure gradient and altimeter and mooring observations to derive an eddy-induced Reynolds stress. Results show that north of the Abrolhos Islands (situated near the shelf break between 28.2° and 29.3°S), the alongshore momentum balance is between the pressure gradient and wind stress. South of the Abrolhos Islands, the Leeuwin Current is highly unstable and strong eddy kinetic energy is observed offshore of the current axis. The alongshore momentum balance on the offshore side of the current reveals an increased alongshore pressure gradient, weakened alongshore wind stress, and a significant Reynolds stress exerted by mesoscale eddies. The eddy Reynolds stress has a −0.5 Sv (Sv ≡ 106 m3 s−1) correction to the Indonesian Throughflow transport estimate from Godfrey’s island rule. The mesoscale eddies draw energy from the mean current through mixed barotropic and baroclinic instability, and the pressure gradient work overcomes the negative wind work to supply energy for the instability process. Hence the anomalous large-scale pressure gradient in the eastern Indian Ocean drives the strongest eddy kinetic energy level among all the midlatitude eastern boundary currents.

Wear mechanisms of coated mixed-ceramic tools during finish hard turning of hot tool die steel

2009 ◽  
Vol 224 (1) ◽  
pp. 183-193 ◽  
Author(s):  
J S Dureja ◽  
V K Gupta ◽  
V S Sharma ◽  
M Dogra
Keyword(s):  
Feed Rate ◽  
Wear Mechanisms ◽  
Hard Turning ◽  
Flank Wear ◽  
Cutting Speed ◽  
Protective Layer ◽  
Depth Of Cut ◽  
Work Piece ◽  
Die Steel ◽  
Mixed Ceramic

The present study aims to investigate the wear mechanisms of a TiN-coated mixed ceramic tool prevalent under different machining conditions during hard turning of hot tool die steel. The different wear mechanisms observed are abrasion wear at low cutting speed, low feed rate, and highest work piece hardness; formation of protective layer and built-up edge (BUE) resulting from tribochemical reactions between constituents of tool and work piece material at moderate speed. High temperature accompanied by high cutting speed resulted in the removal of the protective layer and suppressed the BUE formation. Hard carbide particles of work material at a higher feed rate severely gouged the tool flank land. Chipping and brittle fractures were observed at very low and high depth of cut. Adhesion of work piece material followed by plastic deformation and notching was clearly visible at low work piece hardness. The influence of cutting speed, feed rate, depth of cut, and work piece hardness on the progressive tool flank wear, and flank wear rate (VBr-μm/km) in the steady wear region was also analysed.

Sign in / Sign up

Export Citation Format

Share Document