2. (30 Pts) A turbo-compressor is used in some car engines to increase the pressure and...

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2. (30 Pts) A turbo-compressor is used in some car engines to increase the pressure and density of intake air delivered to the engine. An intercooler heat exchanger is used to re-cool the hot air from the compressor (TH~ 150C) before it is delivered to the engine, further increasing the density. A typical intercooler should reduce the compressed air temperature to Tc ~ 50C. A number of companies sell finned pre-intercooler pipes that they claim can be installed between the compressor and main intercooler to help reduce the intake air temperature (e.g., https://www.siliconeintakes.com/front-mount-intercooler/pre-intercooler-cooling-pipe-p-223.html). Consider the following situation: The pre-intercooler pipe has inner diameter ID = 43 mm, outer diameter OD = 51 mm, and length L = 230 mm. = The hot air-to-wall heat transfer coefficient on the inside of the pipe is hi 175 W m K. = The pre-intercooler has an array of 50 rectangular fins on its outside (see picture). The fins have uniform thickness tfin = 3 mm and extend Lfin 13 mm out from the pipe. The heat transfer coefficient from the finned surface to the ambient air is ho = 100 W m K-. The intake air flow rate is m = 0.15 kg s and enters the pre-intercooler pipe at TH=150C. The pre-intercooler pipe rejects heat to the surrounding air at T = 25C. Intake Air Compressor Hot Compressor Outlet (TH) TURBINE EXHAUST TURBINE INLET Possible Location for "Pre-Intercooler" Pipe Intercooler INTE MA FOLD EXHAUST MANIFOLD Air Delivery to Engine (Tc) ENGINE a. (8 Pts) Draw a thermal resistance network from the hot air flowing through the "pre- intercooler pipe" to the surrounding ambient air. b. (14 Pts) Calculate all of the thermal resistances in the system and the overall thermal resistance between the hot air in the intercooler pipe and the surrounding ambient air. c. (8 Pts) Determine the heat transfer rate from the pre-intercooler pipe to the surrounding air. Considering the information in the prompt at the top of the page, does the pre-intercooler pipe significantly increase the overall cooling capacity, or is it a scam/placebo? Quantitatively justify your conclusion. 2. (30 Pts) A turbo-compressor is used in some car engines to increase the pressure and density of intake air delivered to the engine. An intercooler heat exchanger is used to re-cool the hot air from the compressor (TH~ 150C) before it is delivered to the engine, further increasing the density. A typical intercooler should reduce the compressed air temperature to Tc ~ 50C. A number of companies sell finned pre-intercooler pipes that they claim can be installed between the compressor and main intercooler to help reduce the intake air temperature (e.g., https://www.siliconeintakes.com/front-mount-intercooler/pre-intercooler-cooling-pipe-p-223.html). Consider the following situation: The pre-intercooler pipe has inner diameter ID = 43 mm, outer diameter OD = 51 mm, and length L = 230 mm. = The hot air-to-wall heat transfer coefficient on the inside of the pipe is hi 175 W m K. = The pre-intercooler has an array of 50 rectangular fins on its outside (see picture). The fins have uniform thickness tfin = 3 mm and extend Lfin 13 mm out from the pipe. The heat transfer coefficient from the finned surface to the ambient air is ho = 100 W m K-. The intake air flow rate is m = 0.15 kg s and enters the pre-intercooler pipe at TH=150C. The pre-intercooler pipe rejects heat to the surrounding air at T = 25C. Intake Air Compressor Hot Compressor Outlet (TH) TURBINE EXHAUST TURBINE INLET Possible Location for "Pre-Intercooler" Pipe Intercooler INTE MA FOLD EXHAUST MANIFOLD Air Delivery to Engine (Tc) ENGINE a. (8 Pts) Draw a thermal resistance network from the hot air flowing through the "pre- intercooler pipe" to the surrounding ambient air. b. (14 Pts) Calculate all of the thermal resistances in the system and the overall thermal resistance between the hot air in the intercooler pipe and the surrounding ambient air. c. (8 Pts) Determine the heat transfer rate from the pre-intercooler pipe to the surrounding air. Considering the information in the prompt at the top of the page, does the pre-intercooler pipe significantly increase the overall cooling capacity, or is it a scam/placebo? Quantitatively justify your conclusion.