Air at 27°C and a velocity of 5 m/s passes over the small region As (20 mm × 20 mm) on a large surface, which is maintained at Ts = 127°C. For these conditions, 0.5 W is removed from the surface As. To increase the heat removal rate, a stainless steel (AISI 304) pin fin of diameter 5 mm is affixed to As, which is assumed to remain at Ts = 127°C. (a) Determine the maximum possible heat removal rate through the fin. (Hint: look back to Chapter 3 to see which fin case produces the maximum heat transfer.) (b) What fin length would provide a close approximation to the heat rate found in part (a)? (Hint: refer to Example 3.9.) (c) Determine the fin effectiveness, εf. (d) What is the percentage increase in the heat rate from As due to installation of the fin? In other words, what is the percentage increase in q obtained by adding the fin as compared to not having the fin?

Answers 2

Answer:

a) The maximum possible heat removal rate = 2.20w

b) Fin length = 37.4 mm

c) Fin effectiveness = 89.6

d) Percentage increase = 435%

Explanation:

See the attached file for the explanation.

answer img
answer img
answer img
answer img

AI generated Answer

a) The maximum possible heat removal rate through the fin corresponds to the case of an externally finned surface, which is given by q_max = \alpha_f h_f A_s(T_s - T_{\infty} ) where \alpha_f is the fin-to-base thermal conductivity ratio, h_f is the fin heat transfer coefficient, and A_s is the total area of the base surface. b) The fin length that would provide a close approximation to the maximum heat rate is given by L_f \simeq \frac{\alpha_f h_f A_s }{A_c (T_s - T_{\infty} )} where A_c is the cross-sectional area of the fin. c) The fin effectiveness is given by \varepsilon_f = \frac{q_f}{q_max} where q_f is the actual heat rate through the fin. d) The percentage increase in the heat rate from As due to installation of the fin can be calculated as \Delta q = \frac{ q_f - q_0 }{q_0} \times 100 \% where q_0 is the heat rate from As with no fin.

  • Rate an answer:

Do you know an answer? Add it here!

Can't find the answer?

Other related questions that may help you

Which three-dimensional figure has the greatest number of faces? hexagonal prism octagonal pyramid rectangular prism pentagonal pyramid

Answer:

Octagonal pyramid

Step-by-step explanation:

Hexagonal Prism: 8 faces

2 hexagon bases, and 6 faces that connect each side of the bases

Octagonal pyramid: 9 faces

One octagon base, and 8 faces that meet at a point- all extending from each side of the base

Rectangular prism: 6 faces

Two rectangle bases, and 4 faces connecting each side of the bases

Pentagonal pyramid: 6 faces

One pentagon base, and 5 faces that meet at a point- all extending from each side of the base

I recommend searching for a picture of each of the figures to help you understand this.

Answer:

Octagonal pyramid

Step-by-step explanation:

RIGHT ON EDGE

mags wants to know what is the hottest hairstyle trend is in her town. Which is the best group to survey A.Get a list of salons in her town and use a deck of cards to pick 5 of them to visit. Survey all hairstylists that work in each salon. B.Get a list of salons in her town and circle the 5 salons that are close to her house. Survey all the hairstylists that work at each salon C.Go to all the salons where Luna and her friends go. Survey all the hair stylists that work at each salon D. Ask her clients that are celebrities which salons they go to. Survey all the hair stylists that work at each salon

Answer: A

Step-by-step explanation:

The best group to survey is option A. A.Get a list of salons in her town and use a deck of cards to pick 5 of them to visit. Survey all hairstylists that work in each salon.

What is the survey?

Surveys represent the list of questions that should be focused on for extracting particular data from the people. It could be conducted via the phone, mail, internet, malls, etc.

Since mags want to know the hottest hairstyle trend so here he should get the list of towns and then use the deck of cards so that she should pick 5 for visiting them. Therefore, the correct option is a.

EP Electric has identified two new methods to treat its cooling water. Alternative D(for inflow) would treat the raw water with a conventional reverse osmosis system so that the cycles of concentration could be increased from 5 to 20, This will result in water cost savings of $360,000 per year and chemical cost savings of $56,000 per year. The initial cost of the equipment will be $2.3 million with an operating cost of $125,000 per year Alternative B (for blowdown) will treat the cooling tower blowdown water using a highpressure seawater reverse osmosis system to recover most of the water that is sent to an evaporation pond. This option will result in water sav- ings of $270,000 per year. The cost of the system will be $1.2 million with an operating cost of $105,000 per year. Assuming one of the two methods must be installed, determine which is preferred on the basis of the incremental ROR value using MARRof 5%per year, which is a typically low return expected of government projects. Use a 10-year study period with no salvage value for either system. (Note: See Problem 8.41 for more on this situation.)
Complete the following two statements regarding quantum-mechanical concepts associated with the Bohr model of the atom and refinements that resulted from the wave-mechanical atomic model. " Two important quantum-mechanical concepts associated with the Bohr model of the atom are that electrons are particles moving in _______ Enter your answer for the missing word between words "moving in" and "orbitals" in accordance to the question statement discrete orbitals, and electron energy is quantized into Enter your answer for the missing word after words "quantized in" in accordance to the question statement levels . (b) Two important refinements resulting from the wave-mechanical atomic model are that the electron position is described in terms of a Enter your answer for the missing words after words "in terms of a" in accordance to the question statement electron cloud , and electron energy is quantized into both shells and subshells--each electron is characterized by Enter your answer for the missing word after words "is characterized by" in accordance to the question statement quantum numbers."

Answer:

Two important quantum-mechanical concepts associated with the Bohr model of the atom are (1) that electrons are particles moving in discrete orbitals, and (2) electron energy is quantized into shells. (b) Two important refinements resulting from the wave-mechanical atomic model are (1) that electron position is described in terms of a probability distribution, and (2) electron energy is quantized into both shells and subshells--each electron is characterized by four quantum numbers.

Explanation:

Part A:

The two important quantum-mechanical concepts associated with the Bohr model of the atom are:

(1) Electrons are particles moving in discrete orbitals.

(2) Electron energy is quantized into shells.

Part B:

The two important refinements resulting from the wave-mechanical atomic model are:

  1. That electron position is described in terms of a probability distribution.
  2. The electron energy is quantized into both shells and subshells each electron is characterized by four quantum numbers.

Unable to find an answer to your question?

Don't worry! There are several alternative approaches you can try to resolve your query. Here are some tips to help you find answers in different ways:

  1. Reframe your question: Sometimes, the way you phrase your question can limit your search results. Try rephrasing it using different keywords or providing more context to get better results.
  2. Utilize social media: Post your question on social media platforms, particularly those focused on professional or specialized topics. Twitter, LinkedIn, and Facebook groups can connect you with individuals who may have relevant expertise or experiences to share.
  3. Consult subject matter experts: Reach out to experts in the field related to your question. Many professionals are willing to help and share their knowledge. You can connect with them through email, LinkedIn messages, or by attending relevant conferences or events.
  4. Use our website to find your question through the search box above, or you can sign up to ask your question for our big educational community. Our experts will review your question, and you will get a quick and quality answer.
  5. Collaborate with others: If your question is related to a specific project or problem, consider collaborating with others who might have complementary skills or knowledge. Teamwork can lead to innovative solutions and shared insights.

Remember, the process of finding answers often involves persistence, creativity, and an open mind. By exploring various resources, reaching out to others, and being proactive in your search, you increase your chances of finding the information you need. Happy quest for knowledge!

Useful articles

Other Engineering Questions

Login with Google

 or

Forgot your password?

I don't have an account, I want to Register

Choose a language and a region

English

United States

Polski

Polska

Português

Brasil

English

India

English

Philippines

Español

España

Bahasa Indonesia

Indonesia

Türkçe

Türkiye
How much to ban the user?
1 hour 1 day 100 years