hydraulics 4
301. What are the two main types of head losses in pipelines?
Linear losses and local losses
302. What causes linear head losses in pipelines?
Friction in straight sections of the pipeline
303. What is the coefficient of local losses denoted as?
ζ
304. When are the coefficients λ and ζ used in fluid mechanics?
To find hydraulic losses given the flow velocity
305. What property do the coefficients λ and ζ possess when the fluid flows are dynamically similar?
They remain the same regardless of the fluid type
306. What is the term for fluid motion without mixing of layers?
Laminar flow
307. When does the transition from laminar to turbulent flow occur?
At a specific critical velocity (vcrit)
308. What is the critical Reynolds number (Recrit) for pipes with a circular cross-section?
2320
309. What is the primary significance of the Reynolds number in fluid dynamics?
Determining the flow regime (laminar or turbulent)
310. What happens when the Reynolds number (Re) is less than the critical Reynolds number (Recrit)?
The flow is laminar
311. What determines the degree of hydraulic resistance in pipelines?
The ratio of inertia forces to viscous forces
312. Which of the following equations describes the flow of a real fluid?
The Bernoulli equation for a real fluid stream
313. What is the purpose of a Pitot tube in fluid mechanics?
Measuring both pressure and velocity heads
314. Which type of head is associated with the heights to which the liquid will rise in piezometers at the corresponding flow sections?
Piezometric head
315. What is the role of the Venturi tube's diffuser (expanding section)?
To create a pressure drop for flow rate measurement
316. What is the critical Reynolds number (Recrit) for fully developed turbulent flow in pipes?
4000
317. What is the dimensionless coefficient used in determining the critical Reynolds number (Recrit)?
k
318. When the Reynolds number (Re) falls within the range of 2320 to 4000, what type of flow is typically observed?
Transitional, critical flow
319. What is the critical velocity (vcrit) in fluid mechanics directly proportional to?
The kinematic viscosity of the fluid
320. In fluid dynamics, what is the primary determinant for the transition between flow regimes?
The ratio of inertia forces to viscous forces
321. When the Reynolds number (Re) is greater than the critical Reynolds number (Recrit), what type of flow is typically observed?
Turbulent flow
322. Which type of losses in pipelines occur as a result of flow deformation and vortex formation?
Linear losses
323. What is the coefficient of linear losses denoted as?
λ
324. Which of the following can affect the coefficients λ and ζ in fluid dynamics?
Flow type
325. What is the primary significance of the Reynolds number in fluid dynamics?
Determining the flow regime (laminar or turbulent)
326. What is the mode of fluid motion with the mixing of layers called?
Turbulent flow
327. Which of the following statements about the Venturi tube is true?
It creates a local constriction in the pipeline.
328. Which of the following statements about linear head losses in pipelines is true?
They result from friction in straight sections of the pipeline.
329. What does the Pitot tube measure in a fluid flow?
Pressure and velocity
330. What is the coefficient of local losses denoted as?
ζ
331. What determines the flow regime of a fluid in a pipe according to the Reynolds number?
Ratio of inertia forces to viscous forces
332. When the Reynolds number (Re) is less than the critical Reynolds number (Recrit), what type of flow is typically observed?
Laminar flow
333. When is the transition from laminar to turbulent flow observed?
At a specific critical velocity (vcrit)
334. Which type of head is associated with the height to which the liquid will rise due to initial velocity?
Velocity head
335. In fluid dynamics, what property allows us to determine the flow regime of a fluid in a pipe?
Reynolds number
336. What is the purpose of a Venturi tube in a pipeline?
To measure the flow rate or velocity of liquids and gases
337. What type of flow is observed when the Reynolds number (Re) is greater than the critical Reynolds number (Recrit)?
Turbulent flow
338. What determines the degree of hydraulic resistance in pipelines according to the Reynolds number?
Ratio of inertia forces to viscous forces
339. Which equation describes the flow of a real fluid?
The Bernoulli equation for a real fluid
340. What is the mode of fluid motion without mixing of layers called?
Laminar flow
341. What does the Pitot tube measure in a fluid flow?
Pressure and velocity
342. In fluid dynamics, what does the coefficient of local losses (ζ) represent?
Dimensionless value describing local losses
343. Which equation is typically used to determine linear head losses in pressurized pipelines?
Darcy-Weisbach formula