Solved Exam Problem: Hydrostatic Forces on a Curved Gate

MEC516/BME516 Fluid Mechanics: A solved exam problem of hydrostatic forces on a curved gate.

All of the videos in this course, sample exams with solutions, and a copy (pdf) of this solution can be downloaded at:

Course Textbook: F.M. White and H. Xue, Fluid Mechanics, 9th Edition, McGraw-Hill, New York, 2021.

Chapters
00:00 Introduction
00:12 Problem Statement
01:10 Pressure distribution on the curved gate
01:50 Free body diagram of the curved gate
03:20 Solution for the horizontal hydrostatic force, F_H
04:28 Solution for the vertical hydrostatic force, F_V
07:22 Solution for the external vertical force (F_A) to hold gate
13:47 Taking moments about the hinge at B
15:00 Alternate "Method of Imaginary Water" to find F_V

#fluidmechanics #fluiddynamics

[idg_studios]

Thank you so much for your videos. My professor does not give us examples in class and his hand written notes/diagrams are hard to understand. Your stuff is super straightforward with organized diagrams and I greatly appreciate your work

[gulchinaliyeva]

i have been suffering with a single question in my book for an hour... Your video made me understand everything, thank you so so much!!

[alvicgruta]

I love you dont use the concept of imaginary water. such a big help sir 🎉

[mtnaik]

You are a fantastic professor Dr. You've saved me in my civil engineering fluid mechanics class

[airsoft]

Amazing video, something that seems so weird and complicated made simple and intuitive. You are so good at explaining the theory and “how to attack” a problem in a easy to understand way. Please post more similar content, thank you! =)

[saratesfaye]

Dear Sir, won't calculating Fbc be double-counting the weight? Why the force by the hydrostatic pressure is not equal to the weight in this case, because i see your other videos, and you were considering the weight only.

[nanodynamics]

Awesome and detailed solution. Thanks Dr. David

[TRÍLÊNGỌC-on]

Thanks a lot for your explanation Sir. I am stil confused when we put the value of gate's weight and in the book they said the centroid of weight is 2R/pi. Could you help me please

[BetterDeckbuilding]

Why is it that the line of action of Fh is the same as Fx? Summing forces in the x-direction says the magnitudes are the same, but why is it that they act in the same place?

[anton_s]

Thanks for this video! My professor didnt really go over a free body diagram method of doing this and this makes so much more sense -- much more in line with what ive done in previous courses. Thanks!

[TiaanTouring]

Dear sir, at 11:55 you say that there is a uniform distribution load and therefore the Fbc acting on R/2. Why is that? Isn't the load distribution also acting in a circular way? which implies the Fbc from C is 4R/3Pi ?

[lessssssgooooo]

Thanks Dr.David i understand the topic well now after watching your Video on it greetings from Germany.

[TOWARDSTHETRUTH]

Why have you not considered the gravitational acceleration for the vertical forces & weight of the fluid?

[MuhammadDaniyalMechietobe]

Thank youuu Sirr, your way of explanation is tooo good..

[Mechanics]

thanks dr.david for providing the solution of fluid mechanics as pdf on your website

[schwarzmann]

Thank you so much for this example, helped immensely

[connorbishop]

Hello! I'm sorry I am a little confused about F_BC, what exactly is this force. Is it the reactant force due to F_A. Furthermore, why does it act at the center of BC and not at C if it is the reactant force from F_BC. I know this has to due to the depth that it is at, but I am a little confused why it is at the center and if this is the equal and opposite reaction of F_A. Thank you!

[marcusreigen]

Good day sir. I hope u read my comment. I'm confused with regards to the summation of moments for getting the distance of Fv to hinge B. I tried using summation of moment by only considering Fv and Fh since in some problems in getting the distance of Fv, this method works. The only problem is that the distance that im getting for Fv is on the other half therefore i subtract it from the radius=8 to get the answer. The answer I got is the same as yours however I dont understand why this happens and if its considered a correct method. Hope u clear my confusion. Apologies if my english is a bit confusing.

[A.Hisham]

thank you for the video! really informative.
But, what about the weight of the gate, is it negligeable in the calculus? and why?

[menglimkorn]

Why there are two FH on water diagram but only one for Fv, please explain to me I can not get it.