- #1
I think one of your attachments ('127') is for an earlier problem.foo9008 said:Homework Statement
why the force at outlet A shouldn't be 0.0707(12 cos120 - 12)
Homework Equations
The Attempt at a Solution
as we can see from the figure , outlet A make an angle 120 with the horizontal line
You are confusing yourself. Both 126 and 127 were for an earlier problem. Neither has an angle 120 degrees in it. Only 128 matches the text of your post in this thread.foo9008 said:ignore 128 , pls refer to the picture i upload now .
sorr, pls refer to the picture i uploaded now , 129 and 126haruspex said:You are confusing yourself. Both 126 and 127 were for an earlier problem. Neither has an angle 120 degrees in it. Only 128 matches the text of your post in this thread.
No, the correct two images are 128 and 129.foo9008 said:sorr, pls refer to the picture i uploaded now , 129 and 126
Again you are right. But if you look at the next line the correct numerical value is obtained.foo9008 said:why the force at outlet A shouldn't be 0.0707(12 cos120 - 12)
haruspex said:No, the correct two images are 128 and 129.
Again you are right. But if you look at the next line the correct numerical value is obtained.
why Fx means the force of blade acts on water ? shouldn't it be force of water act on blade?haruspex said:No, the correct two images are 128 and 129.
Again you are right. But if you look at the next line the correct numerical value is obtained.
The author has chosen to define Fx and Fy as forces from the blade acting on the water.foo9008 said:why Fx means the force of blade acts on water ? shouldn't it be force of water act on blade?
if i want to directly find the resultant force acting on the pipe bend on the water , how to find it ? what's the equation ?haruspex said:The author has chosen to define Fx and Fy as forces from the blade acting on the water.
I'm not sure what you are asking. If you mean, how to find force of water on blade, just define Fx and Fy in the opposite directions.foo9008 said:if i want to directly find the resultant force acting on the pipe bend on the water , how to find it ? what's the equation ?
i mean find the resultant force acting on the pipe bend by the water , can we define Fx = resultant force acting on the pipe bend by the water instead ofharuspex said:I'm not sure what you are asking. If you mean, how to find force of water on blade, just define Fx and Fy in the opposite directions.
If you mean how to find the resultant force without finding the x and y components, define your axes to be aligned with and perpendicular to the resultant, which is at some unknown angle theta to the incoming water. Then find the components of various lnown forces in those directions. It is just as much work, though.
Sure, you can define it the other way round. It just flips its sign in every equation.foo9008 said:i mean find the resultant force acting on the pipe bend by the water , can we define Fx = resultant force acting on the pipe bend by the water instead of
resultant force acting on the water by the pipe bend ? so , if we define Fx = resultant force acting on the pipe bend by the water, then Fx = 0.0707(12cos 120 -12) +0.1414(12 cos60 -12 ) = 2.12KN(to the left)
is it correct to do so ?
i just couldn't understand why the author define Fx as resultant force acting on water by the pipe bend ?
Why we can't just not flip the equation and do as in the notes, but define fx as force acting on the bend by the water? I don't understand why the author define fx as force acting on the water by bend and do it this wayharuspex said:Sure, you can define it the other way round. It just flips its sign in every equation.
I can't think of a reason.foo9008 said:Why we can't just not flip the equation and do as in the notes, but define fx as force acting on the bend by the water? I don't understand why the author define fx as force acting on the water by bend and do it this way
The formula for calculating force at a pipe bend outlet is F = ρQ²K, where F is the force, ρ is the density of the fluid, Q is the volumetric flow rate, and K is the loss coefficient.
The loss coefficient at a pipe bend can be calculated using the following formula: K = 0.0707(12cosθ - 12), where θ is the angle of the bend.
The cosine factor in the force calculation formula takes into account the direction of the flow at the pipe bend. This is important because the force will be different depending on whether the flow is turning towards or away from the bend.
The density of the fluid has a direct impact on the force at a pipe bend outlet. The higher the density, the greater the force will be. This is because a denser fluid will have more mass and therefore will exert more force on the bend.
Yes, this formula can be used for any type of fluid as long as the density and flow rate are known. However, the loss coefficient may vary slightly depending on the viscosity and other properties of the fluid.