The Art of Measuring in the Thermal Sciences

A: Measuring in Thermal Systems: Reducing Errors and Error AnalysisMeasuring the Right Data—Verifying Experimental Boundary ConditionsIntroductionThinking AheadCase StudiesAir Heat Exchanger—Thermal Fin Design/OptimizationExpanding Gas Jet—Impingement Cooling on Pipe WallsLongitudinal Fin Cooling of ElectronicsHeated Pipe-in-Pipe TestingMulti-Pass Refrigerant Loop: Local Heat Transfer CoefficientsConclusionsReferencesMeasurement Error or Data Trend? How to Conduct Meaningful ExperimentsError Analysis in Experimental InvestigationsError AnalysisUncertainty of Category AUncertainty of Category BError PropagationDesign of Experiments for Validation of CFD CalculationsReferencesUncertainty Analysis of Indirect Measurements in Thermal ScienceIntroductionImportance of Uncertainty AnalysisDirect and Indirect MeasurementsObjectivesMeasurement UncertaintySources and Types of UncertaintiesNormal Distribution and Standard DeviationDealing with Indirect MeasurementUncertainty Determination of Individual VariablesUncertainty Determination of a Multivariable FunctionCase StudyDetermination of Uncertainty of Direct MeasurementDetermination of Type A Uncertainty uADetermination of Type B Uncertainty uBCombined Standard Uncertainty uCEvaluation of Uncertainty of Indirect MeasurementsRemarksReferencesModern Error Analysis in Indirect Measurements in Thermal ScienceIntroductionModel, Direct Measurements, and Definition of the Parameters That Are Looked ForStatistical Characterization of Noise and Bias for a Parameter Estimation ProblemStatic Model and Estimation of the Parameters of a Probability LawMeasurement of the Output of a Perfect Dynamical Model and Its Vector FormModel BiasExample of a Binormal Joint DistributionProperties of Random VectorsExample 1: Estimation of a Heat Transfer Coefficient in a One-State ExperimentLeast Squares and Estimation ResidualsLeast Square Sum and ResidualsLinear Least SquaresNonlinear Least SquaresExample 2: Estimation of a Heat Transfer Coefficient through Multiple-Steady State MeasurementsConclusionsReferencesB: Convection Challenges and Energy BalancesWilson Plots and Measurement AccuracyIntroductionWilson Plot MethodEstimation of HTCStandard Errors of the HTC ParametersExperimental Procedure and LimitationsModified Wilson Plot MethodsReynolds Exponent LimitationVariable Property Effects or Fin Resistance LimitationsConstant Thermal Resistance LimitationExperimental Procedure and LimitationsWeighted FitsGeneral Wilson PlotExample ApplicationDataHTC CalculationWilson Plot MethodModified Wilson Plot MethodsWeighted Wilson Plot MethodGeneral Wilson Plot MethodDiscussionReferencesTest Sections for Heat Transfer and Pressure Drop Measurements: Construction, Calibration, and ValidationIntroductionOur Range and ExperienceConstruction of Test SectionTest Section Length and LayoutPressure TransducersDifferential Pressure Transducers with Interchangeable DiaphragmsPressure TapsThermocouplesT-Type ThermocouplesThermocouple PreparationCopper Test SectionsStainless Steel Test SectionsTube-in-Tube Heat ExchangersPt100 ProbesFlow MetersData AcquisitionHeating MethodHeating WireIn-Tube HeatingInsulationFlow-Calming SectionMixing SectionCalibrationPressure TransducersPt100 ProbesThermocouplesDrift and RecalibrationData ReductionUncertainty AnalysisBackgroundBasic Procedure and ExamplesLinear Regression Analysis: PtlOO ProbeLinear Regression Analysis: Pressure Transducer with a 2.2-kPa DiaphragmUncertainty Analysis: Reynolds NumberUncertainty Analysis: Nusselt NumberUncertainty Analysis: Friction FactorValidationUnexplained ChallengesFlow-Calming Section ContentsUpstream Effects Caused by Exit MixerLogging Frequency and Sampling TimeSmall Diameter Copper Test SectionElectric NoiseReferencesStability Evaluation, Measurements, and Presentations of Convective Heat Transfer Characteristics of NanofluidsIntroductionNanofluid Synthesis and Stability EvaluationNanofluid Synthesis and PreparationStability Evaluation of NanofluidsThermophysical Properties of NanofluidsThermal ConductivityViscositySpecific HeatConvective Heat Transfer of Nanofluids—Experimental StudiesNatural Convection and Channel FlowsMeasurements and AccuracyData Reduction and PresentationsEmpirical CorrelationsSummary of Findings of Natural Convection in CavitiesConvective Heat Transfer in MicrochannelsConclusions and RemarksAcknowledgmentsReferencesDetermination of Energy Efficiency of Hot Water Boilers and Calculation of Measurement UncertaintiesIntroductionProcedure for Determining the Energy Efficiency of Hot Water BoilerDetermination of the Nominal Heat OutputDescription of the Hot Water Boiler Testing Plant (Bypass Method)Calculation of the Nominal Heat Output Q̇outCalculation of Heat Input Q̇inCalculation of the Nominal Heat Input Q̇in When Oil Fuel or Solid Fuel Is UsedCalculation of Heat Input Q̇in,r, When Gas Fuel Is UsedEfficiency of Boiler at Full Nominal LoadEfficiency Measurement with the Direct MethodEfficiency Measurement with the Indirect Method of Thermal LossesMeasurement Accuracies and UncertaintiesProcedures for Calculation of the Uncertainty Efficiency in a Hot Water BoilerEvaluation Methods for Measuring ErrorsDefinitionsUncertainty Calculation of Useful Heat OutputUncertainty Calculation of Heat InputVariability of Efficiency MeasurementParametric Analysis and Graphical Depiction of the Effect of the Measured Values of the Qin, Qout, and “n” CalculationsGeneral Conclusions from Parametric Analysis of the Absolute and Relative % Uncertainty of the Boiler EfficiencyReferencesPsychrometric Performance Testing for HVAC&R Components and EquipmentIntroductionPsychrometric ConditioningAirflow DistributionCommon Practices and LimitationsExperimental Evaluation of AirflowApplication of CFD and Effects onto Equipment TestsPsychrometric MeasurementsAir SamplingTemperature SensorsThermocouples (TCs)Resistance Temperature DevicesTemperature Grids and Air MixersRecommendation for Selecting Temperature SensorsPsychrometersRelative Humidity SensorsDew-Point MetersOther RecommendationsAirflow MeasurementsCode Tester/Nozzle BoxAnemometersPitot TubesLeakage TestingControls of Psychrometric Testing FacilitiesSteady-State OperationSafety MechanismsReferencesC: Heat Flux Measurements, Optical Techniques, and Infrared ThermographySurface Temperature Measurement on Complex Topology by Infrared ThermographyIntroductionBasic Theoretical ConsiderationsCamera Types and Practical ApplicationCamera TypesPractical ApplicationWindow MaterialsCamera CalibrationLinearizationNUC: Non-Uniformity CorrectionSingle-Point NUCTwo-Point NUCHigh Dynamic Range (HDR)Position EstimationFocus StackingTemperature CalibrationThe Semiempirical Calibration FunctionThe Improved Calibration TechniqueAdapting the Calibration to Local EffectsSurface CurvatureNon-Constant Offset RadiationMeasurement UncertaintyConclusionReferencesOptical Measurements for Phase Change Heat TransferIntroductionInfrared ThermographyOptical Techniques (Visible Light)Fluorescence-Based Temperature MappingTemperature-Sensitive PaintsPhosphor ThermographyPool and Flow Boiling Measurements Using Temperature-Sensitive PaintsTSP Formulation and CharacterizationTSP CharacterizationTemperature and Pressure DependenceAging of TSPsPool Boiling Test Apparatus and DemonstrationTest Section ConstructionData ReductionPool Boiling MeasurementsFlow Boiling Test Apparatus and DemonstrationTest Section ConstructionData ReductionFlow Boiling MeasurementsPool Boiling Measurements Using Fluorescence MicroscopyConclusionsReferencesPractical Heat Flux MeasurementIntroductionHeat Flux SensingBasic Fundamentals of Temperature and Heat Flux MeasurementOne-Dimensional Planar SensorsInsert Heat Flux GagesCalibrationThermal Measurement Details (Errors to Avoid)Example UsesSummaryHeated Meter Bar Techniques: What You Should Know and WhyIntroduction and PrincipleCharacterizing Heat Transfer PropertiesThe Heated Meter Bar TechniquesAssessing Uncertainty in the HMBTCalculating Uncertainty Using the HMBTMonte Carlo Simulation of UncertaintiesAn Example: High-Precision Thermal Interface Material TestingAn Example: High-Heat-Flux Forced Convective BoilingSummaryInverse Problems in Heat Conduction: Accurate Sensor System CalibrationIntroductionMathematical ModelOne-Dimensional, Semi-Infinite Heat Conduction ProblemHeat Conduction SystemSystem IdentificationInverse Heat Conduction Problem Solution Using NISISensor System CalibrationApplicationFurther ApplicationsSummaryAcknowledgmentsReferencesD: Measuring in Two-Phase FlowChallenges and Advances in Measuring Temperatures at Liquid–Solid InterfacesIntroductionIntrusive Techniques: Thermistors and ThermocouplesOverview and State-of-the-Art SolutionsLocal Measurement of Surface Temperature with High Temporal ResolutionEroding-Type Fast Response ThermocouplesThin-Film ThermocoupleHeat Flux Exchanged in Liquid–Solid InterfacesTransient Heat Transfer Assuming a Semi-Infinite SolidTransient Heat Transfer in a Finite Slab with an Imposed Heat FluxSemi-Intrusive and Non-Intrusive TechniquesOverviewInfrared (IR) Thermography with High Temporal and Spatial ResolutionsWorking Principles and Influencing ParametersCalibration and Data Reduction ProceduresSurface Temperature and Heat Flux Measurements at Liquid–Solid InterfacesFinal Remarks and Future ProspectsAcknowledgmentsReferencesMeasuring Heat Transfer Coefficient during Condensation Inside ChannelsIntroductionApproach Based on Wilson Plot MethodModified Wilson Plot MethodEvaluation of the Experimental UncertaintyDirect Wall Temperature Measurement ApproachLocal MeasurementDetermination of the Local Heat Transfer Coefficient and Vapor QualityEvaluation of the Experimental UncertaintyThe Weighted Least Squares (WLS) MethodResults from the Uncertainty AnalysisConclusionsReferencesOptical Measurement Techniques for Liquid–Vapor Phase Change Heat TransferIntroductionHigh-Speed Videography for the Analysis of BoilingGood Practices, Experimental Biases, and ArtifactsRecent Progresses in the Understanding of Bubble Dynamics Owing to High-Speed VideographyHigh-Speed Videography: A Major Contribution to the Analysis of Flow BoilingLiquid–Vapor Interface Characterization Using Confocal MicroscopyIntroductionFunctional PrincipleExperimental Implementation of the Optical Method and ExamplesWall Temperature Measurement of a Transparent Tube during Flow Boiling Using IR CameraFunctional Principle of Measurement with IR CameraExperimental Configuration and Data AcquisitionPost-Processing AnalysisDetermination of the Wall Emissivity by Means of a Calibration ProcedureConclusionReferencesSelected Problems of Experimental Investigations during Refrigerants Condensation in MinichannelsIntroductionSome Research Problems of Compact MinicondensersThe Mechanism of Refrigeration Condensation in Minichannels and Basic Research ProblemsMethodology of Experimental Investigations of Refrigerants Condensation in MinichannelsExperimental Investigations of Thermal and Flow Characteristics of CondensationInvestigations of Two-Phase Flow Structures during Refrigerants Condensation in MinichannelsSummaryReferences
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