Finite Element Simulation of Cutting Forces in Turning Ti6Al4V Using DEFORM 3D

2013 ◽  
Author(s):  
Kosaraju Satyanarayana ◽  
Anne Venu Gopal ◽  
Popuri Bangaru Babu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Cutting Forces ◽  
Experimental Results ◽  
Shear Friction ◽  
Shear Friction Factor ◽  
Deform 3D

Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties though they are classified as difficult to machine materials. As the experimental tests are costly and time demanding, metal cutting modeling provides an alternative way for better understanding of machining processes under different cutting conditions. In the present work, a finite element modeling software, DEFORM 3D has been used to simulate the machining of titanium alloy Ti6Al4V to predict the cutting forces. Experiments were conducted on a precision lathe machine using Ti6Al4V as workpiece material and TiAlN coated inserts as cutting tool. L9 orthogonal array based on design of experiments was used to evaluate the effect of process parameters such as cutting speed and feed with a constant depth of cut 0.25 mm and also the tool geometry such as rake angle on cutting force and temperature. These results were then used for estimation of heat transfer coefficient and shear friction factor constant, which are used as boundary conditions in the process of simulation. Upon simulations a relative error of maximum 9.07% was observed when compared with experimental results. A methodology was adopted to standardize these constants for a given process by taking average values of shear friction factor and heat transfer coefficient, which are used for further simulations within the range of parameters used during experimentation. A maximum error of 9.94% was observed when these simulation results are compared with that of experimental results.

A General Approach to Analysis of Flow and Heat Transfer in Packed Beds

2008 ◽  
Author(s):  
Aleksander Vadnjal ◽  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Surface Area ◽  
Hydraulic Diameter ◽  
Experimental Results ◽  
Transfer Coefficients ◽  
Internal Surface Area ◽  
The Media

It is postulated that proper scaling will collapse the multiplicity of data for friction and heat transfer coefficient to a usable reasonably general formulation by choosing the hydraulic diameter as Dh=4·〈m〉Sw where <m> is the average porosity and Sw is the surface area per unit volume. The chosen hydraulic diameter allows the transformation and comparison of correlation equations and experimental results obtained for diverse media morphologies. Also, it allows experimentally-determined characteristics of the media to be related to the closure relationship derived from the VAT analysis. The numerical results of closure are presented and are compared to various experimental results. The Nusselt number is based on the media internal local surface average transfer coefficient and the friction factor is the local internal value. Results obtained by VAT closure using direct numerical simulation show reasonable agreement between calculated local friction factors and local heat transfer coefficients and data confirming that the friction factor and heat transfer coefficient when correctly scaled can be computed numerically with satisfactory results. This conclusion will enable one to optimize the effectiveness of a compact heat exchanger in terms of porosity and internal surface area.

Finite Element Simulation of Nickel-Based Alloy Cutting Process Based on DEFORM- 3D

2011 ◽  
Vol 175 ◽  
pp. 352-356 ◽  
Author(s):  
Jia Long Ren ◽  
Chun Yan Zhang ◽  
De Peng Yuan
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Cutting Force ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Cutting Process ◽  
Average Temperature ◽  
Deform 3D

To analysis cutting mechanism and heat transfer coefficient of Ni-based superalloy IN718, this paper introduced a three-dimensional finite element model for cutting process based on DEFORM-3D V6.1, and cutting force Fy and cutting temperature T under different feed rate f , cutting speed v and back engagement ap were obtained. The temperature variation during cutting process under different cooling method was analyzed. The simulation results indicate that the influence of back engagement ap on the cutting force Fy is the greatest, while that of cutting speed v is minor; and for cutting temperature T, influence of cutting speed v is the greatest, while that of back engagement ap is minor. Influence of heat transfer coefficient on highest temperature and average cutting force Fy is minor, but its influence on average temperature is quite obvious. Greater heat transfer coefficient is less average temperature.

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

scholarly journals Enhancement of Impingement Heat Transfer With the Crossflow Normal to Ribs and Pins Between Each Row of Holes

2018 ◽  
Author(s):  
Abubakar M. El-Jummah ◽  
Gordon E. Andrews ◽  
John E. J. Staggs
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Pressure Loss ◽  
Cross Flow ◽  
Experimental Results ◽  
Hole Density ◽  
Impingement Heat Transfer ◽  
The Cross ◽  
Flow Maldistribution

Impingement heat transfer investigations with obstacle (fins) on the target surface were carried out with the obstacles aligned normal to the cross-flow. Conjugate heat transfer (CHT) computational fluid dynamics (CFD) analysis were used for the geometries previously been investigated experimentally. A 10 × 10 row of impingement jet holes or hole density, n, of 4306 m−2 with ten rows of holes in the cross-flow direction was used. The impingement hole pitch X to diameter D, X/D, and gap Z to diameter, Z/D, ratios were kept constant at 4.66 and 3.06 for X, D and Z of 15.24, 3.27 and 10.00 mm, respectively. Nimonic 75 test walls were used with a thickness of 6.35 mm. Two different shaped obstacles of the same flow blockage were investigated: a continuous rectangular ribbed wall of 4.5 mm height, H, and 3.0 mm thick and 8 mm high rectangular pin-fins that were 8.6 mm wide and 3.0 mm thick. The obstacles were equally spaced on the centre-line between each row of impingement jets and aligned normal to the cross-flow. The two obstacles had height to diameter ratios, H/D, of 1.38 and 2.45, respectively. Comparison of the predictions and experimental results were made for the flow pressure loss, ΔP/P, and the surface average heat transfer coefficient (HTC), h. The computations were carried out for air coolant mass flux, G, of 1.08, 1.48 and 1.94 kg/sm2bar. The pressure loss and surface average HTC for all the predicted G showed reasonable agreement with the experimental results, but the predictions for surface averaged h were below the measured values by 5–10%. The predictions showed that the main effect of the ribs and pins was to increase the pressure loss, which led to an increased flow maldistribution between the ten rows of holes. This led to lower heat transfer over the first 5 holes and higher heat transfer over the last 3 holes and the net result was little benefit of either obstacle relative to a smooth wall. The results were significantly worse than the same obstacles aligned for co-flow, where the flow maldistribution changes were lower and there was a net benefit of the obstacles on the surface averaged heat transfer coefficient.

Convective Heat Transfer Characteristics of Silver-Water Nanofluid Under Laminar and Turbulent Flow Conditions

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Lazarus Godson ◽  
B. Raja ◽  
D. Mohan Lal ◽  
S. Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Pure Water ◽  
Convective Heat Transfer Coefficient ◽  
Experimental Results

The convective heat transfer coefficient and pressure drop of silver-water nanofluids is measured in a counter flow heat exchanger from laminar to turbulent flow regime. The experimental results show that the convective heat transfer coefficient of the nanofluids increases by up to 69% at a concentration of 0.9 vol. % compared with that of pure water. Furthermore, the experimental results show that the convective heat transfer coefficient enhancement exceeds the thermal conductivity enhancement. It is observed that the measured heat transfer coefficient is higher than that of the predicted ones using Gnielinski equation by at least 40%. The use of the silver nanofluid has a little penalty in pressure drop up to 55% increase 0.9% volume concentration of silver nanoparticles.

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