![]() ![]() ![]() But looking at the literature, I found that, by carefully avoiding all possible disturbances, people had reached Reynolds number as high as 1,000,000 still having laminar flow through the pipe. I was really surprised because also I knew the magic value of 2300. And this was found also by changing the pipe diameter. In my apparatus, with very low disturbances, my critical Reynolds number (transition from laminar to turbulent flow) turned out to be about 14,000. I was repeating the Newton's experiment also with water (newtonian fluid) and a carefully designed bellmouth at the pipe entrance. But let us go to your question, which I assume relates to newtonian fluids. I was checking if viscoelastic fluids delayed the onset of turbulence in the flow through round pipes. The question brings me back to my master thesis, about 54 years ago. Unfortunately, time will be required to go through and process the knowledge contained within. You will not find a concise answer for your question, but this reference will provide a lot of relevant insight for you. This section will also refer you to other sections of the text for related information. "Determination of the point of instability for a prescribed body shape." There are a number of figures containing data that can help elucidate the extent of the transition region based upon certain assumptions regarding your geometry and flow field. Ed., the classic text by Hermann Schlichting. ![]() If you are interested in the details, I recommend you consult Chapter 17, "Origin of Turbulence II" in Boundary Layer Theory, 7th. That distance delineates the spatial region while the temporal factor can be determined by the timing (speed) of the external or main flow field. In a simple analysis, the region that interests you is confined between the points of instability and transition. The physics involved include the external flow field, the pressure gradient and of course the geometry of the solid surface (if present) adjacent to the flow field. Transition is linked to the growth of small instabilities in the flow field, but the link is not straightforward. Suitable for pharmaceuticals, laboratory food and beverages, etc.This question is big and open-ended. is a professional purification equipment manufacturer. ![]() Wuxi Lenge Purification Equipment Co., Ltd. For example, when we pour the oil into cooking, the movement state of the edible oil is the phenomenon of laminar flow. When the fluid is more viscous, the phenomenon of laminar flow will be more obvious. And the turbulent flow also has the effect of vortex lifting, which is the main factor for the sediment to be transported in suspension.Ģ. Therefore, the carrying capacity of turbulent flow is stronger than that of laminar flow. Turbulent flow not only has viscous shear stress, but also additional shear stress caused by the turbulent flow of fluid particles while laminar flow has only viscous shear stress. The phenomenon of laminar flow is mainly transport because the laminar flow and turbulent flow have different mechanical characteristics. Laminar flow is to form a uniform flow layer after the air passes through the high-efficiency filter at a certain wind speed, so that the clean air flows in a vertical unidirectional flow, thereby ensuring the high cleanliness required by the process in the working area.ġ. The fluid flows at a low speed in the tube, and the streamlines move forward in parallel without crossing, and its Reynolds number is less than 2000. Laminar Airflow, a professional term in fluid mechanics, is a flow state of the fluid. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |