Calculate velocity of streams impinging at differing angles

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Discussion Overview

The discussion revolves around calculating the velocity of two streams that collide at differing angles, with a focus on the implications of elastic collisions. Participants explore the momentum and energy balances involved in the collision, questioning the consistency of the results obtained from these different approaches.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant outlines a method to calculate the forward and backward mass flow rates and velocities after the collision, assuming a 100% elastic collision.
  • Another participant argues that the final directions of the streams are incompatible with the concept of elastic collisions, suggesting that macroscopic energy may not be conserved.
  • Some participants express doubt about the assumption that the streams will move only along the x-axis after the collision, indicating that they should bounce back along the y-axis instead.
  • A participant mentions that the scenario is hypothetical and serves as a control for future theories on energy dissipation during collisions.
  • There is a discussion about the implications of the momentum of the streams and how it affects the direction of the backward flow, with some participants questioning the accuracy of the original diagram used to represent the situation.
  • Another participant suggests that energy conservation could be achieved by splitting each stream into two parts that deflect without speed loss and recombine with parts from the other stream.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the assumptions regarding energy conservation and the final directions of the streams after the collision. Multiple competing views remain regarding the interpretation of elastic collisions in this context.

Contextual Notes

There are unresolved questions about the assumptions made regarding the collision dynamics, particularly concerning the energy conservation and the behavior of the streams post-collision. The discussion also highlights the potential inaccuracies in the initial diagram representing the collision scenario.

  • #31
A.T. said:
You can always transform into a reference frame, where the fluid in one of the incoming streams is initially at rest, while the fluid in the other stream initially moves along one axis only. Then you solve the (potentially simpler) problem there, and transform the resulting outgoing velocities back to the original frame.

Just don't confuse the direction of the velocity of the fluid in a stream with the orientation of the stream. They are parallel in your original frame, but not necessarily in other frames.
I'm going to try to switch to the zero momentum frame of reference. Should I start a new thread as I am definitely going to need help?
 

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