![]() ![]() Only the low-frequency modes, such as translational and rotational, can absorb energy (heat) at lower temperatures. The specific heat reflects the energy taken up by translational (kinetic), rotational, and vibrational modes. įor gases, the Cp and Cv have different values because gases are compressible. The heat required to raise the temperature of 1 kg of water by 1 K is 4184 joules, i.e., the specific heat capacity of water is 4184 J⋅kg − 1⋅K − 1. These two values are almost the same for condensed matter (liquids or solids) because the condensed matter is almost incompressible. The Specific Heat Capacity (specific heat) is typically measured and reported at constant Pressure ( Cp) or constant volume (Cv). The SI unit of specific heat capacity is joule per kelvin per gram, J⋅g − 1⋅K − 1 (or kJ⋅kg − 1⋅K − 1 ), The Specific-Heat Capacity, C, is the heat required to raise the temperature by 1K per mole or kg. Steam Generator Devices in the MHI store.Steam Generator Service and Parts for low kW Units.The velocity is the same for the prototype and the model, so Vp / Vm = 1. Since the prototype is a one-fifth scale model, Ap / Am = (1/5)^2 = 1/25. The ratio of the drag force on the prototype (Fp) to the drag force on the model (Fm) is then:įp / Fm = (Ap / Am) * (ρp / ρm) * (Vp / Vm)^2 V is the velocity (which is the same for the model and the prototype) ![]() ρ is the fluid density (which is different for air and water) A is the cross-sectional area (which is proportional to the square of the length scale) Cd is the drag coefficient (assumed to be the same for the model and the prototype, since they have the same shape) In this case, the students have measured the drag force on a scale model of their submarine in a wind tunnel, and they want to estimate the drag force on the full-size submarine in water. The design team builds a one-fifth scale model to test in their university's wind tunnel. The water is freshwater (a lake) at T = 15 C. The overall length of the prototype submarine is 2 4.85 m, and its student designers hope that it can travel fully submerged through water at 0.440 m/s. ![]() The drag force on the prototype submarine is estimated to beĪ student team is to design a human-powered submarine for a design competition. Estimate the drag force on the prototype submarine at the given conditions.įor water at 7 = 15C and atmospheric pressure, p = 999.1 kg/m3 and = 1.138x 10-3 kg/m-s.įor air at 7 = 25C and atmospheric pressure, p = 1.184 kg/m3 and = 1.849 105 kg/m-s. They are careful to run the wind tunnel at conditions that ensure similarity with the prototype submarine. The students measure the aerodynamic drag on their model submarine in the wind tunnel. SOLVED: A student team is to design a human-powered submarine for a design competition. ![]()
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