The energy transferred from the anterior chamber of the eye through the cornea varies considerably depending on whether a contact lens is worn. Treat the eye as a spherical system and assume the system to be at steady state. The convection coefficient
Values of the parameters representing this situation are as follows:
- Construct the thermal circuits. labeling all potentials and flows for the systems excluding the contact lens and including the contact lens. Write resistance elements in terms of appropriateparameters.
- Determine the heat loss from the anterior chamber with and without the contact lens in place.
- Discuss the implication of your results.
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Fundamentals of Heat and Mass Transfer
- 1- The energy transferred from the anterior chamber of the eye through the cornea varies considerably depending on whether a contact lens is worn. Treat the eye as a spherical system and assume the system to be at steady state. The convection coefficient ho is unchanged with and without the contact lens in place. The cornea and the lens cover one-third of the spherical surface area. T he T h Anterior chamber Contact lens Cornea are as follows: Values of the parameters representing this situation r 10.2mm, r 12.7 mm, r3= 16.5 mm, Teoj= 37°C, Teoo = 21°C, ki = 0.35 W/m.K, k2 0.80 W/m.K, h 12 W/m2.K, ho 12 W/m2.K. (a) Construct the thermal circuits, labeling all potential and flows form the systems excluding the contact lens and including the contact lens. Write resistance elements in terms of appropriate parameters (b) Determine the heat loss from the interior chamber with and without the contact lens in place (c) Discuss the implication of your results.arrow_forwardA thermometer has a time constant of 10 s and behaves as a first-order system. It is initially at a temperature 30°C and then suddenly subjected to a surrounding temperature of 150°C. Calculate the 90 percent rise time and the time to attain 99 percent of the steady-state temperature. Repeat these calculations for a time constant of 5 s and compare the results with that of the previous casearrow_forwardunder steady-state conditions. If you are given T1 = 200 °C and T2 = 164 °C, determine: a) the conduction heat flux, q,.cond, in m2 W from x = 0 to x = L b) if the dimensions of the triangle ares 15 mm and h 13 mm, calculate the heat transfer due to convection, q,y, in W at x = L Finsulation T2 T T = 20°C h = 500 W/m2.K Triangular Prism x L x 0 L= 50 mm k = 100 W/m-Karrow_forward
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The wall consists of outer plaster with a thickness of 0.1N cm. thick k = 0.3N W/m °C, reinforced concrete with a thickness of N/2 cm = 0.8 W/m °C, k = 0.6 W/m °C gypsum honey interior plaster with a thickness of 1 cm. Find the total heat loss. To reduce heat loss by 80%, how many cm should be used from insulating material with k = 0.001 (N+N2) W/m °C (calculations will be made for single and double glazing). Heaplay the required amount of drain before and after the work is made.arrow_forwardA plane wall of thickness 8cm and thermal conductivity k=5W/mK experiences uniform volumetric heat generation, while convection heat transfer occurs at both of its surfaces (x= -L, x= + L), each of which is exposed to a fluid of temperature T∞ = 20˚C. The origin of the x-coordinate is at the midplane of the wall. 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If temperature information is not provided, evaluate properties T = 300K a)oroidal shape with diameter D = 50mm and cross-sectional area AC = 5 mm², with thermal conductivity k = 2.3W / (mK) The surface of the toroid is exposed to a refrigerant corresponding to a convective coefficient eta = 50 W/( m2.k) b)A long stainless steel heated bar (AISI 304), with rectangular cross section, and dimensions w = 3mm , W = 5mm and L = 100mm . the bar issubjected to a refrigerant that provides a heat transfer coefficient of h =15 W/(m2 K) on all exposed surfaces. c)A long extruded aluminum tube (2024 Alloy) with internal dimensions and external w = 20 mm and W = 24 mm , respectively, suddenly submerged in water, with a convective coefficient of h =…arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning