A thermocouple junction of 1.0-mm in diameter is inserted in a large chamber to measure the...

A thermocouple junction of 1.0-mm in diameter is inserted in a large chamber to measure the temperature of hot gas flowing through the chamber. The hot gas has a velocity of 2 m/s and temperature (Tg) at 800 K. The chamber surface (Ts) is maintained at 500 K.

(a) If the thermocouple is at room temperature, Ti when it is inserted in the chamber, calculate the time required for the temperature difference, (Tg–T) to reach 2% of the initial temperature difference Tg-Ti . Neglect radiation and conduction through the leads. Properties of the thermocouple junction are approximated as k = 100W/mK, c = 385 J/kgK and  = 8920 kg/m3 , while those of the hot gases may be assumed to have the properties of air at atmospheric pressure.

(b) If the thermocouple junction has an emissivity of 0.5, what is the steady state temperature of the thermocouple junction?

(c) The emissivity of the thermocouple junction can be controlled through application of a thin coating. How would changes in the emissivity affect the temperature measurement error? Compute the steady state junction temperature for emissivities in the range 0.1  ɛ  1. Results are to be presented in graphical and / or tabular forms and should be accompanied by substantial discussion supported by heat transfer fundamentals.

(d) Suggest ways to eliminate the temperature measurement error

Expert Solution

samet mamat answered 2 years ago

A spherical thermocouple junction 1.0 mm in diameter is inserted in a combustion chamber to measure...

A spherical thermocouple junction 1.0 mm in diameter is inserted in a combustion chamber to measure the temperature ?T? of the products of combustion. The hot gases have a velocity of V= 5 m/s. (a) If the thermocouple is at room temperature, Ti,when it is inserted in the chamber, estimate the time required for the temperature difference, ?T?-T, to reach 2% of the initial temperature difference, ?T?-Ti. Neglect radiation and conduction through the leads. Properties of the thermocouple junction are...

Question 3 A sheathed thermocouple is placed in a combustion chamber to measure the temperature of...

Question 3 A sheathed thermocouple is placed in a combustion chamber to measure the temperature of the gases at a certain point in the process. The thermocouple reading is 1110K and the inside wall temperature was measured at 1008K. The thermocouple has a surface area of 10 mm2 . (a) A pitot probe is used to measure the velocity of the gas stream in the vicinity of the thermocouple tip. It measures a difference in static and dynamic pressure of...

1. A black thermocouple measures the temperature in a chamber with black walls. If the air...

1. A black thermocouple measures the temperature in a chamber with black walls. If the air around the thermocouple is at 20°C, the walls are at 100°C, and the heat transfer coefficient between the thermocouple and the air is 15 W /m2·°C, what temperature will the thermocouple read

If each of the seven individuals pulls water in with a velocity of 3.0 mm per second through an incurrent siphon 1.0 mm in diameter

If each of the seven individuals pulls water in with a velocity of 3.0 mm per second through an incurrent siphon 1.0 mm in diameter, and the combined water from all seven individuals exits the shared excurrent siphon, which has a diameter of 1.5 mm, what is the velocity of the water as it leaves the excurrent siphon?

How much 1.0 mm diameter copper wire would it take to equal the resistance of one...

How much 1.0 mm diameter copper wire would it take to equal the resistance of one 100 Ω resistor? The resistivity of copper is 1.68*10-8 Ωm b) What would be the current if this wire was connected to a 12.0 V battery? c) How many electrons per second pass by a point on the wire? d) If this wire was coiled up and submerged in 100 mL of water at 20oC, how long would it take for the water to...

A capacitor consists of two 4.3-cm-diameter circular plates separated by 1.0 mm. The plates are charged...

A capacitor consists of two 4.3-cm-diameter circular plates separated by 1.0 mm. The plates are charged to 130 V , then the battery is removed. A) How much energy is stored in the capacitor? U_C = __J How much work must be done to pull the plates apart to where the distance between them is 2.0 mm? W = _J

A current of 5 mA flows through a 2 mm inner-diameter glass tube filled with 1.0...

A current of 5 mA flows through a 2 mm inner-diameter glass tube filled with 1.0 mol dm-3 NaCl(aq) solution in the anode compartment in addition to a CH3COONa (aq) solution in the cathode compartment. The boundary created between the two solutions moves 6.05 mm towards the anode in 10 minutes. Calculate the transport number of the chloride ion in the solution.

A 4.0-cm-diameter parallel-plate capacitor with a 1.0 mm spacing is charged to 1000 V. A switch...

A 4.0-cm-diameter parallel-plate capacitor with a 1.0 mm spacing is charged to 1000 V. A switch closes at t =0s, and the capacitor is discharged through a wire with 0.20? resistance. Part A Find an expression for the magnetic field strength inside the capacitor at r =1.0cm as a function of time t (where t is in ps). Part B Draw a graph of B versus t.

The propeller shaft of a large ship has an outside diameter of 350 mm and inside...

The propeller shaft of a large ship has an outside diameter of 350 mm and inside diameter 250mm. the shaft is rated for a maximum of shear stress 62 MPa. 1) if the shaft is runnning at 500 rpm what is the maximum power that can be transmitted without exceeding allowable stress. 2) if the rotational speed of the shaft is doubled but the power requirements unchanged what happens to the shear stress in the shaft? calculate valures.

A thermocouple is used to measure a known temperature of 25oC. A set of measurements is...

A thermocouple is used to measure a known temperature of 25oC. A set of measurements is taken. 29.6% of the measurements are found within ±1 oC of 25oC (the sample mean value is 25oC). We assume the temperature to be a random variable following a Gaussian distribution function. Please answer the below questions and upload your work as a single file (preferably PDF or jpeg). You need to show ALL work. Question 1. Show that the standard deviation of the...

Question