lab report 1

Lab Report #1: Page 1 TEXAS TECH UNIVERSITY DEPARTMENT OF CIVIL, ENVIRONMENTAL, AND CONSTRUCTION ENGINEERING Lab Report #1: Fluid Properties CE 3105 – Fluid Laboratory Section: 303 Team Number: 2 Instructor: Theodore Cleveland Authors: Bradley Brooks Conner Jeter Ruben Ramos Gabriel Vega Date of Experiment: 1/29/2024 Date of Submission: 2/5/2024

Lab Report #1: Page 2 Table of Contents Theory ........................................................................................................................................................ 3 Apparatus ................................................................................................................................................... 7 Results ........................................................................................................................................................ 9 Discussion ................................................................................................................................................. 10 Data Appendix ......................................................................................................................................... 11 Error Calculations ................................................................................................................................... 11 Sample Calculations ................................................................................................................................ 11 List of Figures Figure 1: Shear Stress Between Two Parallel Planes Figure 2: Hydrometer and Other Specific Tools Used Figure 3: Water Density and Specific Gravity Graph Figure 4: Saltwater Density and Specific Gravity Graph Figure 5: Glycerin Density and Specific Gravity Graph List of Tables Table 1: Recorded and Calculated results from the Density Measurements Table 2: Calculated Salt Mass Results Table 3: Recorded and Calculated Results of Specific Gravity Table 4: Kinematic and Dynamic Viscosity Table 5: Data Appendix with Calculated Results

Lab Report #1: Page 4 SpecificWeight = Weight Volume γ = mg V At constant pressures and temperature, the specific weight of a fluid is constant. Specific Gravity , another significant property of fluids, is defined as the ratio of a fluid's density to the density of water at the same temperature. Notably, water has a specific gravity of 1.0. Fluids with a higher density than water exhibit a specific gravity greater than 1, whereas those with a lower density than water have a specific gravity less than 1. The formula for specific gravity can be defined as: SpecificGravity = ρ s ρ H 2 O As a dimensionless quantity derived from the ratio of two densities, specific gravity plays a pivotal role in determining whether a fluid will float or sink in water. Moreover, it facilitates consistent comparisons of fluids across various units. Fluids, defined as substances unable to completely resist shear stresses, initiate flow when subjected to such stresses. Notably, different fluids exhibit varying flow rates under identical magnitudes of shear stress. Viscosity serves as a metric for a fluid's resistance to shear stress, akin to internal resistance. Conceptually, viscosity represents the frictional forces between layers of fluid in relative motion. Dynamic viscosity quantifies the tangential force per unit area needed to move one horizontal plane relative to another at a unit velocity while maintaining a unit distance apart.

Lab Report #1: Page 5 According to Newton’s law of viscosity, the shear stress τ is proportional to the velocity gradient. Dynamic viscosity μ is the constant of proportionality. It can be represented with the following equation: τ = μ du dy Figure 1: Shear Stress between two Parallel Planes Dynamic Viscosity can be described as a ratio of shear force to the velocity gradient. It can be written in units of lb ft ∗ s (US). It can be found, especially in fluid mechanics, to encounter the

Lab Report #1: Page 7 Apparatus Figure 2: Hydrometer and Other Specific Tools Used Variables Used/Measured  Mass of beaker (g)  Beaker + Fluid (g)  Volume (mL)  Density of solution (g/mL)  Specific Gravity  Density of Sphere (kg/m^3)  Diameter of steel ball (in)  Diameter of Graduated Cylinder (mm)  Length (m)  Time (s)  Kinematic Viscosity (m^2/s)  Dynamic Viscosity (kg*m/s)  Density of Fluid (kg/m^3)

Lab Report #1: Page 8 Procedure Part One: Density 1. Take the temperature of the fluid using a thermometer. 2. Use a scale to weigh the provided beaker. 3. Fill the beaker with the fluid and record the combined mass (beaker + fluid) using the scale. 4. Measure the volume of the fluid in the beaker accurately, either by using a graduated cylinder or estimating it by observing the fluid level in the beaker. 5. Repeat all the above steps for each of the three liquids, ensuring consistency in the measurement process. Part Two: Specific Gravity 1. Carefully place the calibrated hydrometer into the fluid, ensuring it is fully immersed, and record the value corresponding to the lower meniscus. 2. Repeat the measurement process three times for each assigned fluid to ensure consistency and accuracy. Part Three: Viscosity 1. Take the steel ball (sphere) assigned to your group and measure its diameter. 2. Gently release the ball into the ball guide, ensuring it falls smoothly. 3. Record the volume readings corresponding to the upper and lower level markers (i.e., the two rubber bands). 4. Begin timing with the stopwatch as soon as the ball reaches the first level marker (upper rubber band). 5. Stop the stopwatch once the ball reaches the second level marker (lower rubber band). 6. Use the density of stainless steel (7800 kg/m³) to calculate the volume of the sphere based on the recorded volume readings. 7. Repeat the entire process for each sphere assigned to your group.

Lab Report #1: Page 10 Figure 5. Glycerin Density vs. Specific Gravity Table 4. Part 2: Kinematic and Dynamic Viscosity Variable Mean (kg/ms) Std. Dev. (kg/ms) Kinematic Viscosity .000576 .742 Dynamic Viscosity .000656 .846 Discussion During the experiment, several complications that may have occurred influenced the set experiment are the following. One is the inclusion of foreign agents within the precision 10ml (about 0.34 oz) dropper, and the beakers being potentially contaminated with other reactants. And for the following experiments proceeding the instruments have yet to be calibrated to a set 0. And the final experiment of viscosity on the surface of an object could have human and instrumentation error. The first experiment consisting of the fluid's density cannot be completely accessed without a shadow of skepticism because the container/ beaker is potentially influenced by other products residual from past experiments. Despite our efforts to rinse and wipe the influence from small traces although minuscule are still present. For further consideration, a set of containers should be reserved for certain fluids such water and salt water and glycerin. The second experiment preceding is the specific gravity. A major issue was the instrument of measurement struggle to give a reading to glycerin, perhaps due to its uncalibrated nature. One other notion to consider is the opportunity that is presented when an external force influences the placement of the instrument in the fluid. For the final experiment since the method of recording involves human judgement from a recording. It is subject to some form of biases and weights that prohibit it from being completely empirical. Therefore, the analysis should be considered with the variance of a sd of a human factor in mind.

Lab Report #1: Page 11 Data Appendix Error Calculations Some of the calculations we found can have minor inaccuracies in the data with human error on reporting density calculations in the lab. It may have appeared that some of the density calculations for water may be inaccurate, which may have been caused by an accidental water spill on the scale of the scale. Sample Calculations ρ = M V = ( 166.85 − 115.86 ) g 30 mL = 1.70 g mL mean = Σ a i n = ( 1.70 + 1.64 + 1.60 ) 3 = 1.65 g mL Std .dev . = √ ( 1 n − 1 ) Σ ( x i − x ) 2 = √ ( 1 3 − 1 ) ( ( 1.7 − 1.65 ) 2 + ( 1.64 − 1.65 ) 2 + … ) = .05050 g Mass of Salt = ( M s = V sw ( ρ sw − ρ w ) ) = 30 ( 1.01 − 1.00 ) = .300 g Length = V π d 2 4 = 400 mL π ( 60 mm ) 2 4 = 0.14 m Velcocity = L t avg = .14 m ( 1.76 + 2.27 ) 2 = 0.0693 m s

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