CFD Coursework 2023 Your report shall be submitted in pdf format (the ANSYS Fluent files shall also be uploaded as a single zip file read the guide for the simulations submission - please do NOT zip the pdf report and the ANSYS Fluent files into a single .zip file). Reports containing more than 14-pages (excluding the cover page, table of contents, references, appendix) will be penalized. The report shall be prepared using the dedicated template (which also includes the cover sheet and the initial table where the student shall indicate which questions have been addressed). According to the University of Strathclyde regulations, all files will be scanned using Turnitin to detect plagiarism issues. Submissions of the coursework without the simulation files will result in a 60% penalisation. The Ansys files will be checked to verify that their contents reflect what has been reported in the coursework and verify that the associated license number is that released by the University of Strathclyde (files prepared with other licenses are not allowed). The report shall be submitted no later than 12 noon Monday, March 25, 2024. After this time submissions will be penalised. The maximum submission size is 500MB. Submissions by email will not be considered. CFD Coursework 2023 Your report shall be submitted in pdf format (the ANSYS Fluent files shall also be uploaded as a single zip file read the guide for the simulations submission - please do NOT zip the pdf report and the ANSYS Fluent files into a single .zip file). Reports containing more than 14-pages (excluding the cover page, table of contents, references, appendix) will be penalized. The report shall be prepared using the dedicated template (which also includes the cover sheet and the initial table where the student shall indicate which questions have been addressed). According to the University of Strathclyde regulations, all files will be scanned using Turnitin to detect plagia Somissions of the coursework we simulation les will result in a 60% penalisation. The Ansys files will be checked to verify that their contents reflect what has been reported in the coursework and verify that the associated license number is that released by the University of Strathclyde (files prepared with other licenses are not allowed). The report shale Submitted no 120on Monday, March 25, 2024. After this time submissions will be penalised. The maximum submission size is 500MB. Submissions by email will not be considered./n/n DEPARTMENT OF MECHANICAL & AEROSPACE ENGINEERING Coursework- Smoke Stack Chimney System with Trickle Vents Computer Aided Engineering and Design(16429) Contents 1. Introduction 2. Geometry Size and Fluid Properties ………….. 25 3. Simulation Set-up.... 6 4. Analysis and final report........ 6 5. Notes/FAQ - other cues and suggestions to make your coursework successful 9 6. References .. 10 DEPARTMENT OF MECHANICAL & AEROSPACE ENGINEERING Smoke Stack Chimney System with Trickle Vents 1. Introduction Chimney or smokestack configurations are widespread in the artificial environment. They are a typical feature of modern society's fluid waste disposal methods as witnessed by the various visible gaseous emissions into the atmosphere from domestic and industrial smokestacks (McGrattan et al. [1]) and from cooling towers or mobile exhausts. Other 'non-visible' examples are represented by the releases of liquid into coastal water, rivers and lakes from a variety of (industrial, municipal and agricultural) sources, mining and oil extraction operations (Jirka [2]; Tomàs et al. [3]), chemical reactors and various plants for waste treatment and desalination facilities (Oliver et al. [4]). Many other variants can be found in the specific field of energy production, where such configurations are a characteristic feature of thermal discharges from nuclear and fossil-fueled electricity generation plants (Martineau et al. [5]; Lee and Asce [6]; Fregni et al. [7]). They can also exist at a smaller scale in typical problems relating to the cooling of computer mother boards and related CPUs and memories (Sun and Jaluria [8]; Biswas et al. [9]) or in combustion chambers as a result of the presence of holes or orifices for fuel injection and dilution (Issac and Jakubowski [10]; Baltasar et al. [11]). Similar concepts also apply to the manufacturing industry, where gas furnaces are commonly used for the heat treatment of metals (Viskanta [12]). In the built (civil engineering) environment, such configurations are widespread in emergency ventilation and air conditioning systems in buildings (Venkatasubbaiah and Jaluria [13]; Subudhi et al. [14]; Morsli et al. [15,16]; Harish [17]) and can be found, in general, in every technological situation in which a heat exchanger is required. Given the diversity and rich spectrum of circumstances in which such configurations can be encountered and the myriad technological applications briefly reviewed above, generalizations are rather difficult. Many situations are possible in principle depending on the specific case considered. However, all these cases share a common factor, namely, the existence of localized regions where the temperature is higher than that of the surroundings (typically the area located at the bottom of the considered chimney or smokestack configuration). This typically leads to the onset of "thermal convection" [18, 19] (heated fluid tends to become lighter and therefore it rises through the chimney). Two fundamental situations are possible in principle: Fluid rises in the chimney only due to thermal convection (completely "natural" phenomenon), or a fixed mass flow rate is forced through the chimney (this leading to "mixed" natural-forced convection through the chimney). Here, we will concentrate on mixed natural- forced convection. The considered configuration can be seen in Figure 1. This geometry has a symmetry plane. It consists of a region (called “heat chamber”) delimited externally by walls with a constant (high) temperature and an upper region of larger horizontal extension (the chimney) delimited externally by adiabatic (no heat exchange) solid walls. The symmetry axis is indicated with a dot-dashed line. The distance of the walls from the symmetry axis for the heat chamber and the chimney is denoted by b and B, respectively (with B > b). Due to the heating effect of the walls, the fluid inside the heat chamber expands (its density reduces) and therefore it becomes “lighter”. The lighter hot fluid tends to rise in the heat chamber and enter the chimney region. As the velocity of these naturally-induced currents is in general relatively small, this flow can 2 DEPARTMENT OF MECHANICAL & AEROSPACE ENGINEERING be considered incompressible and the Boussinesq approximation can be used. Due to the fluid rising through the heat chamber and the chimney, new colder fluid (having temperature Tc) tends to be sucked into the heat chamber through the inlet region located at the bottom of the heat chamber. However, the velocity of the rising currents can be enhanced by injecting some air directly into the chimney as shown in Fig. 1 (forced flow aiding natural flow). Moreover, the temperature of the air injected directly into the chimney can be modulated in order to reduce the overall temperature of air released into the external atmosphere (e.g., by injecting air at a temperature smaller than the ambient temperature Tc). Cold Fluid Injection (Uforced Tforced) B Outlet Hot element Chimney Thot Heat chamber Inlet T 60 air Figure 1 Schematisation of the Heat Chamber (channel)-Chimney system. The vector ğ is the gravity acceleration The characteristic numbers for natural (buoyant) and imposed (forced) flows are the Rayleigh and Reynolds numbers, respectively, i.e.: 3 DEPARTMENT OF MECHANICAL & AEROSPACE ENGINEERING Ra = gB+ATL³ να U forced L Re = V where L is a reference length. It is worth recalling that for an incompressible flow, the amount of fluid entering the system per unit time is always equal to the amount of fluid leaving the system per unit time, (i.e. at any instant an amount of relatively hot fluid leaves the system through the outlet section at the top, which is equal to the amount of cold fluid entering the system from the bottom plus the fluid injected from the side). As shown in Fig.1, in general, the proper numerical simulation of this problem requires that the numerical domain (the overall mesh) is not limited to the heat chamber and the chimney, it must also include two extra areas corresponding to a certain portion of the external environment (located under the heat chamber and over the chimney, respectively). Table 1 Fluid properties for the Boussinesq model Property Assigned Value Fluid Air Density Model Boussinesq Density (p) Specific Heat (Cp) Model Specific Heat (Cp) Thermal Conductivity Model Thermal Conductivity( λ) Viscosity Model 1.225 Kg/m³ Constant 1006 J/KgK constant 0.0242 W/mK constant Viscosity (μ) 1.7894x10-5 Kg/ms Thermal Expansion Coeff. Model Thermal Expansion Coeff.(BT) Kinematic viscosity (v) constant 0.0033 K-1 1.46x10-5 m²/s Thermal diffusivity( a) 1.96x10-5 m²/s + DEPARTMENT OF MECHANICAL & AEROSPACE ENGINEERING 2. Geometry Size and Fluid Properties 210 15 25 5 70 40 40 15 09 60 60 08 X 25 40 40 50 30 70 Figure 2 Dimensions of the Heat Chamber-Chimney System (lengths are measured in millimetres, they shall be multiplied by 10-3 in order to have the corresponding ones in meters) 5