Secondary flow spanwise deviation model for the stators of NASA middle compressor stages

A model of the spanwise variation of deviation for stator blades is presented. Deviation is defined as the difference between the passage mean flow angle and the metal angle at the outlet of a blade element of an axial compressor stage. The variation of deviation is taken as the difference above or below that predicted by blade element, (i.e., two-dimensional) theory at any spanwise location. The variation of deviation is dependent upon the blade camber, solidity and inlet boundary layer thickness at the hub or tip end-wall, and the blade channel aspect ratio. If these parameters are known or can be calculated, the model provides a reasonable approximation of the spanwise variation of deviation for most compressor middle stage stators operating at subsonic inlet Mach numbers

An experimental investigation of internal area ruling for transonic and supersonic channel flow

A simulated transonic rotor channel model was examined experimentally to verify the flow physics of internal area ruling. Pressure measurements were performed in the high speed wind tunnel at transonic speeds with Mach 1.5 and Mach 2 nozzle blocks to get an indication of the approximate shock losses. The results showed a reduction in losses due to internal area ruling with the Mach 1.5 nozzle blocks. The reduction in total loss coefficient was of the order of 17 percent for a high blockage model and 7 percent for a cut-down model

Off-design correlation for losses due to part-span dampers on transonic rotors

Experimental data from 10 transonic fan rotors were used to correlate losses created by part-span dampers located near the midchord position on the rotor blades. The design tip speed of these rotors varied from 419 to 425 m/sec, and the design pressure ratio varied from 1.6 to 2.0. Additional loss caused by the dampers for operating conditions between 50 and 100 percent of design speed were correlated with relevant aerodynamic and geometric parameters. The resulting correlation predicts the variation of total-pressure-loss coefficient in the damper region to a good approximation

Development and Validation of a Tool to Measure Patient Assessment of Clinical Compassion

Importance: Clinician compassion is a vital element of health care quality. Currently, there appears to be no validated and feasible method for health care organizations to measure patient assessment of clinician compassion on a large scale. Objective: To develop and validate a tool for measuring patient assessment of clinician compassion that can be used in conjunction with the Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) survey. Design, Setting, and Participants: This prospective cohort study took place from June 1 to August 30, 2018, at a US academic health care system among a pilot cohort consisting of 3325 adult patients and a validation cohort consisting of 3483 adult patients, both of whom had an outpatient clinic visit and completed the CG-CAHPS survey. Main Outcomes and Measurements: After a comprehensive literature review, 12 candidate survey items were developed. Face and construct validity were performed. Candidate items were disseminated to patients in conjunction with the CG-CAHPS survey in a series of 2 studies: (1) exploratory factor analysis in one cohort to determine the factor structure and the most parsimonious set of items; and (2) validity testing in a second cohort using confirmatory factor analysis. Reliability was tested using Cronbach α. Convergent validity was tested with patient assessment of clinician communication and overall satisfaction questions from CG-CAHPS survey. Results: Overall, 6493 patient responses were analyzed. The mean (SD) age was 60 (15) years, 4239 patients (65.3%) were women, and 5079 (78.2%) were white. Exploratory factor analyses identified a 5-item compassion measure to be the most parsimonious. Confirmatory factor analyses found good fit. The compassion measure demonstrated good internal consistency (α = 0.94) and convergent validity (clinician communication: ρ = 0.44; overall satisfaction: ρ = 0.52) but reflected a patient experience domain (compassionate care) distinct from what is currently captured in the CG-CAHPS survey. Conclusions and Relevance: A simple 5-item tool to measure patient assessment of clinician compassion was developed and validated for use in conjunction with CG-CAHPS survey

Validation of a 5-Item Tool to Measure Patient Assessment of Clinician Compassion in Hospitals

BACKGROUND: We previously validated a 5-item compassion measure to assess patient experience of clinician compassion in the outpatient setting. However, currently, there is no validated and feasible method for health care systems to measure patient experience of clinician compassion in the inpatient setting across multiple hospitals. OBJECTIVE: To test if the 5-item compassion measure can validly and distinctly measure patient assessment of physician and nurse compassion in the inpatient setting. DESIGN: Cross-sectional study between July 1 and July 31, 2020, in a US health care network of 91 community hospitals across 16 states consisting of approximately 15,000 beds. PATIENTS: Adult patients who had an inpatient hospital stay and completed the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey. MEASUREMENTS: We adapted the original 5-item compassion measure to be specific for physicians, as well as for nurses. We disseminated both measures with the HCAHPS survey and used confirmatory factor analysis for validity testing. We tested reliability using Cronbach\u27s alpha, as well as convergent validity with patient assessment of physician and nursing communication and overall hospital rating questions from HCAHPS. RESULTS: We analyzed 4756 patient responses. Confirmatory factor analysis found good fit for two distinct constructs (i.e., physician and nurse compassion). Both measures demonstrated good internal consistency (alpha \u3e 0.90) and good convergent validity but reflected a construct (compassionate care) distinct from what is currently captured in HCAHPS. CONCLUSION: We validated two 5-item tools that can distinctly measure patient experience of physician and nurse compassion for use in the inpatient hospital setting in conjunction with HCAHPS