Solution of Problems Involving Grease Flow in Straight Pipe or Tubing

1967 ◽  
Vol 19 (11) ◽  
pp. 429-432
Author(s):  
S.W. Rein ◽  
J.R. Brehmer ◽  
E.J. Gesdorf ◽  
J. Wegmann
Keyword(s):  
Straight Pipe ◽  
Grease Flow

EXPERIMENTAL STUDY ON FLAME PROPAGATION IN A STRAIGHT PIPE

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Siti Zubaidah Sulaiman ◽  
Rafiziana Md Kasmani ◽  
A. Mustafa
Keyword(s):  
Experimental Study ◽  
Flame Propagation ◽  
Experimental Work ◽  
Diameter Ratio ◽  
Straight Pipe ◽  
Pipe Length ◽  
Operating Condition ◽  
Consistent Trend ◽  
Length To Diameter Ratio

Flame propagation in a closed pipe with diameter 0.1 m and 5.1 m long, as well as length to diameter ratio (L/D) of 51, was studied experimentally. Hydrogen/air, acetylene/air and methane/air with stoichiometric concentration were used to observe the trend of flame propagation throughout the pipe. Experimental work was carried out at operating condition: pressure 1 atm and temperature 273 K. Results showed that all fuels are having a consistent trend of flame propagation in one-half of the total pipe length in which the acceleration is due to the piston-like effect. Beyond the point, fuel reactivity and tulip phenomenon were considered to lead the flame being quenched and decrease the overpressures drastically. The maximum overpressure for all fuels are approximately 1.5, 7, 8.5 barg for methane, hydrogen, and acetylene indicating that acetylene explosion is more severe. 

scholarly journals Effects of Temperature on the Flow and Heat Transfer in Gel Fuels: A Numerical Study

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 821
Author(s):  
Qin-Liu Cao ◽  
Wei-Tao Wu ◽  
Wen-He Liao ◽  
Feng Feng ◽  
Mehrdad Massoudi
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Transport System ◽  
Apparent Viscosity ◽  
Thermal Design ◽  
Straight Pipe ◽  
Heating Wall ◽  
Supply Pressure ◽  
Flow And Heat Transfer ◽  
The Mean

In general, rheological properties of gelled fuels change dramatically when temperature changes. In this work, we investigate flow and heat transfer of water-gel in a straight pipe and a tapered injector for non-isothermal conditions, which mimic the situations when gelled fuels are used in propulsion systems. The gel-fluid is modeled as a non-Newtonian fluid, where the viscosity depends on the shear rate and the temperature; a correlation fitted with experimental data is used. For the fully developed flow in a straight pipe with heating, the mean apparent viscosity at the cross section when the temperature is high is only 44% of the case with low temperature; this indicates that it is feasible to control the viscosity of gel fuel by proper thermal design of pipes. For the flow in the typical tapered injector, larger temperature gradients along the radial direction results in a more obvious plug flow; that is, when the fuel is heated the viscosity near the wall is significantly reduced, but the effect is not obvious in the area far away from the wall. Therefore, for the case of the tapered injector, as the temperature of the heating wall increases, the mean apparent viscosity at the outlet decreases first and increases then due to the high viscosity plug formed near the channel center, which encourages further proper design of the injector in future. Furthermore, the layer of low viscosity near the walls plays a role similar to lubrication, thus the supply pressure of the transport system is significantly reduced; the pressure drop for high temperature is only 62% of that of low temperature. It should be noticed that for a propellent system the heating source is almost free; therefore, by introducing a proper thermal design of the transport system, the viscosity of the gelled fuel can be greatly reduced, thus reducing the power input to the supply pressure at a lower cost.

Dynamics of Treatment Device for Die Casting of Metals

2015 ◽  
Vol 669 ◽  
pp. 327-334 ◽  
Author(s):  
Juraj Ružbarský ◽  
Rastislav Majerník ◽  
Petr Hrabě ◽  
Petr Valášek
Keyword(s):  
Die Casting ◽  
Working Environment ◽  
Regulation System ◽  
Work Culture ◽  
Input Quantity ◽  
Treatment Equipment ◽  
Casting Cycle ◽  
Grease Flow ◽  
Output Quantity

The aforementioned proves that the grease flow in mould treatment equipment can be regarded as a regulation system with the input quantity by medium pressure p1 above the grease level and with the output quantity by the grease flow speed.The utilization of treatment equipment for die casting of metal enhances both the working environment and work culture during die casting of metals. Application of grease flow regulation results in better repeatability of die casting cycle which positively influences the quality of castings.

An Encounter with Lattice Boltzmann for Biomedical Applications: Interactive Simulation to Support Clinical and Design Decisions

2021 ◽  
Author(s):  
Simone Ferrari ◽  
Simone Ambrogio ◽  
Andrew J Narracott ◽  
Adrian Walker ◽  
Paul D Morris ◽  
...  
Keyword(s):  
Real Time ◽  
Vortex Shedding ◽  
Lattice Boltzmann ◽  
Personalised Medicine ◽  
Free Field ◽  
Sudden Expansion ◽  
Patient Specific ◽  
Interactive Simulation ◽  
Straight Pipe ◽  
Karman Vortex

Abstract Medical device design for personalised medicine requires sophisticated tools for optimisation of biomechanical and biofluidic devices. This paper investigates a new real-time tool for simulating structural and fluid scenarios - ANSYS Discovery Live - and we evaluate its capability in the fluid domain through benchmark flows that all involve steady state flow at the inlet and zero pressure at the outlet. Three scenarios are reported: i. Laminar flow in a straight pipe, ii. vortex shedding from the Karman Vortex, and iii. nozzle flows as characterised by an FDA benchmark geometry. The solver uses a Lattice Boltzmann method requiring a high performance GPU (nVidiaGTX1080, 8GB RAM). Results in each case were compared with the literature and demonstrated credible solutions, all delivered in near real-time: i. The straight pipe delivered parabolic flow after an appropriate entrance length (plug flow inlet conditions), ii. the Karman Vortex demonstrated appropriate vortex shedding as a function of Reynolds number, characterised by Strouhal number in both the free field and within a pipe, and ii the FDA benchmark geometry generated results consistent with the literature in terms of variation of velocity along the centreline and in the radial direction, although deviation from experimental validation was evident in the sudden expansion section of the geometry. This behaviour is similar to previous reported results from Navier-Stokes solvers. A cardiovascular stenosis example is also considered, to provide a more direct biomedical context. The current software framework imposes constraints on inlet/outlet boundary conditions, and only supports limited control of solver discretization without providing full field vector flow data outputs. Nonetheless, numerous benefits result from the interactive interface and almost-real-time solution, providing a tool that may help to accelerate the arrival of improved patient-specific medical devices.

Sign in / Sign up

Export Citation Format

Share Document